text:
How to mount userdata_b in stot_a in A/B partition device?
I have a Tissot (mi a1) with TWRP dual booted by separating vendor_a, vendor_b, userdata_a, userdata_b. It is dual booted by cosmicdan's twrp with Resurrection remix ( slot_a) official and Dotos official ( slot_b). I want to mount userdata_b in resurrection remix or vice verse.
I have already tried these steps by no result.

create a folder named 'data2' in " /data/local/tmp/data2" .
open terminal.
run su.
Enter "mount -o rw /dev/block/mmcblk0p52 /data/local/tmp/data2" (as 52 is my userdata_b partition).
no error showing but nothing mounted.

Is there any way to mount this?

Go to android update if it's update is available than the phone would have to be connected to a power source while it rebooted to recovery mode and actually flashed the update.All in, you're talking 30 minutes to an hour to install an update, and nobody has time for that. Even disregarding that hurdle, many users would just ignore the update out of fear for the bugs and UI changes it might bring, leaving their systems dangerously exposed to malware and hacks.
When you take a new phone out of its box, the operating system is installed on the first hard drive (partition "A"). When an update becomes available, it gets downloaded and installed to the second hard drive (partition "B").
The next time you restart your phone, it simply boots off of the "B" partition instead, which means you're now running the new Android update.A/B system updates, also known as seamless updates, ensure a workable booting system remains on the disk during an over-the-air (OTA) update.
This reduces the likelihood of an inactive device afterward, which means fewer device replacements and device reflashes at repair and warranty centers. This approach is already explored successfully by other commercial-grade operating systems, such as ChromeOS, and Android 8.0 comes with the necessary platform changes to conduct streaming updates.
Allow to cancel a proxy resolution request
1 Fix terminating a transfer while resolving proxies
2 Add unittest for TerminateTrasnfer between ranges
3 Cleanup the RetryTimeoutCallback()
A/B system updates affect:
Interactions with the bootloader
Partition selection
The build process
OTA update package generation
The existing dm-verity feature guarantees the device will boot an uncorrupted image. If a device doesn't boot, because of a bad OTA or dm-verity issue, the device can reboot into an old image.

My system is already rooted and custom recovery and custom os installed, with dual booted.


text:
Can not install apks from File Manager or browser?
In the answer to this question I specifically discovered that I could not install the VLC nightlies. It had nothing to do with that answer, which was on a question about which version of VLC was right for that device. But that question was in fact inspired by this problem: I never previously had an APK I couldn't install by merely downloading, when I am in the Android Web Browser, and it downloads the APK, I can click on it in the notification applet at the top. When I do, it says

Can not open file

When I open that file up with the LineageOS Files Manager, com.android.documentsui I get the same error. Now, I'm wanting to know what specifically is borked about just the VLC packages? Does anyone else get this problem? Why is that pm install ./appname.apk in the shell works, but the GUI doesn't?
I'm using LineageOS 14.1-20180616, based on Android 7.1.2.

Have you allowed installing from unknown locations in the settings menu?

@Ankush yep, it worked for installing probably tens of apks, this is some kind of problem that I'm kind of sure is either specific to the apk being malformed, or to filemanager, or the apk-parsing library. Don't know where to start except to say, I installed f-spot through the browser just fine. I don't think the browser/file manager is spawning right to pm, because that works.

It is possible that the content/media type for the apk file is set wrong, so the file manager does not know the type of the file (as in it may be ignoring the extension, and relying solely on the media type (application/vnd.android.package-archive).

@Ankush I've update with a url to the apk, you're welcome to take a look at the package and see if anything pops out at you. If you can help identity the issue, I'll file a bug, because I'm thinking it is one, I just don't do much android dev.

I would try another file manager just to be sure, then file as a bug. I can't try to install it on my device, as my phone does not have an ARM processor.

this question really requires someone with extensive packaging experience on Android/apk, I think I'd look harder if there was nothing obviously out of place there, I'll wait to see how to trouble shoot these problems and if someone smarter can save me some time shooting in the dark on this.

@EvanCarroll v3.0.11 installs fine, but I had your same (random) issue a while ago, with apps completely unrelated to each other. In my case, it was a LineageOS regression, so try updating to the latest weekly before retrying the installation.

@DeathMaskSalesman I'm using LineageOS, but I'll try right now -- my version is pretty new.

@DeathMaskSalesman no joy, now I'm using June 16 LineageOS 14.1 and it's still not working.

@DeathMaskSalesman figured out and self-answered.

@Ankush figured it out and self-answered.

Installing
With the  LineageOS File Manager
It seems that inside the File Manager, there are two discrete things Download a directory, and Downloads some broken nonsense shortcut link:

Does not work: On the left nav, you'll see Images Videos Audio Recent, and then Downloads Documents, and SM-P600. Installing from the Downloads on the right bar, gives this error.
Works: Going into the device at the bottom of the left nav (which is actually just a link to /data/media/0 and then clicking on Download will take you Download which is actually different from Downloads (plural and on the Left Nav). From this you can install the APK.

With the CLI

Enable ADB in the Settings
Run adb shell on the host
Browse to /sdcard/Downloads or /data/media/0/Download with cd. If you're unsure where the apk is located try running
find / -name 'VLC*-ARMv7.apk

Locate the apk and install with pm
pm install ./VLC*-ARMv7.apk

The problem
The problem seems to be that VLC web server answers the request with a response that has content-type: application/octet-stream like this,
$ curl -s -I "https://nightlies.videolan.org/build/android-armv7/VLC-Android-3.0.11-20180618-0249-ARMv7.apk"
HTTP/2 200
server: nginx/1.15.0
date: Tue, 19 Jun 2018 03:16:06 GMT
content-type: application/octet-stream
content-length: 25048251
last-modified: Mon, 18 Jun 2018 06:05:02 GMT
etag: "5b274b8e-17e34bb"
accept-ranges: bytes
x-clacks-overhead: GNU Terry Pratchett
strict-transport-security: max-age=31536000

Rather than application/vnd.android.package-archive. This means that you can't install through the browser, or the Downloads shortcut. This is because APK files are just zip files:
$ file VLC-Android-3.0.11-20180618-0249-ARMv7.apk
VLC-Android-3.0.11-20180618-0249-ARMv7.apk: Zip archive data, at least v2.0 to extract

So what the File Manager and browser are trying to do is open them as such -- and you don't have something that hands Zip archive data 2.0+

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
Is stereoscopic vision via OTG and 2 USB cameras possible?
I'm thinking of making a stereoscopic night vision device by using 2 USB cameras connected via OTG (type C) to my Android phone. I've already tested 1 USB camera and some VR App from the Play Store and it was a success.
Will 2 cameras work if connected to the same OTG cable via a USB splitter/hub of some sort? Is there a way (or app) to display one camera over half of the screen and the other camera in the other half? Is it even possible to have 2 cameras powered and displayed at the same time?

Is it even possible to have 2 cameras powered and displayed at the same time?

It's possible and supported on Android by a number of APK, but never worked for me.
I just purchased USB camera endoscope and plan to install 2 or 4 of them via USB OTG hub (active or passive).
The problem is, APK searchable via Google Play don't support extra features in trial or free mode. On the other hand, it makes no sense to buy one another APK, over and over again just for a test to learn it failed to work for me.
The only APK which worked for me with my new USB camera endoscope is the one named in the manual, "AN98", but I don't get HD image resolution as claimed by a manufacturer. I get a very, very, very, low resolution to work in video mode 30 FPS.
Other endoscope APK failed to show any video or claim connection problems.
So to answer the question: Yes, you can. Try every APK which is relevant and claiming to support 2 USB OTG cameras via a passive or active hub.

Regarding the app AN98, did you mean this "AN98" on the Play Store?

Yes, AN98 from Play store or direct APK download
from
--www.kkmoom.com/an99.apk
or
--www.kkmoom.com/pc.rar for PC
the issue is my endoscope camera comes with 10m cable and Android rejects it
explained why:
"http://www.yourcablestore.com/USB-Cable-Length-Limitations-And-How-To-Break-Them_ep_42-1.html
"https://superuser.com/questions/64744/maximum-length-of-a-usb-cable/64747#64747

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Is it possible to completely disable phone calling on Android?
I've disable the built-in phone app but an a voice over IP app took its responsibilities, I killed that too, disabled notification and tweak everything I could find except for turning off the ringtone in the settings and the phone will still ring, except I can't answer because there's no app for phone calls!
When I receive a phone calls there's a lingering notif as usual I always delete it along with the millions other notifs Android gets nonstop--it's really annoying, I never tapped on it because it does nothing, I remembered however that this version of Android brings more stuff at the first tap. I spent the last two hours trying to remember my own phone number to call myself and bring up the notification, upon tapping it it let me to the system app Phone Call Management which is not blockable. I want to reinstall my VoIP app, it requires to have a ringtone so it can ring too; is there another way around this?
BTW, I also installed phone call blockers, but don't really help in here.
Thanks!

You can remove the SIM card or replace it with a data-only SIM if you don't want to make or receive phone calls at all.

If it is an LTE capable phone then set it to LTE only, when a person tries to call you it would seem as though you are busy and there wont be any ringing, you would still get SMS though

@AguThadeus Only of the carrier doesn't support VoLTE, although many do.

There is no such thing as a data-only card around here, they all incl unlimited all except for data--all carriers; funny thing is I want to limit all except for data. Carriers know people don't make calls/texts anymore, the only calls traversing their netwks are from other ops harassing customers to switch to their own crappy networks...and business calls which would fall under the latter category. Sometimes they manage to trick less savvy custmrs who are on a contract into switching and they make the switch and suddenly that user has to pay the remainder of his/her contract right away + fees.

"along with the millions other notifs Android gets nonstop" -> On the multiple Android phones I had, this wasn't the case. Don't blame Android for installing millions of apps.

Try MTK Engineering kit. You can disable calls from that by turning radio off. Alternatively, use in dial pad *#*#4636#*#* and a window pops up. Now select phone information and scroll down to find the radio option. Now turn off the radio. Then you will not receive any calls. Otherwise you can use airplane mode as well.

If it turns radio off, it will also turn mobile data off. To achieve that, one can simply switch off the SIM in QuickSettings, or take the SIM out. But my guess is that's not what OP wants.

I also have another method first open phone app also known as dialer now find settings from right up corner open the settings, now select call settings>call baring>all incoming calls now just disable them no call will come now but you can use your mobile data you also need barring password of your sim operator but in some cases it was 1234 or 0000 may you find this is in different way because difference of android but good luck.

Thanks! This seems to be what I need. I can't change it though, I get and "Unexpected response from network" but just knowing the option is there I'm going to try to pressure my carrier on this. Thanks again!

Most welcome @Vita if this isn't help tell your device name ,andriod version and root or non rooted then i may help you.

There is one hack by which you can block your incoming calls.
Go to Settings -> Call settings -> Call forwarding
Now Click on Always forward and enable it to forward the calls to a wrong number.
This will ensure that calls will not come to you and the caller get the tone that call is being forwarded and number is wrong.
You can disable Call forwarding anytime you want.
Hope this will help.

I just had this problem, no sound, but ringtones did work. I installed hangup call and a headphone switch to speaker... that did not work but it did tell me what the issue really was and it was this: the phone thought it was in call EVEN AFTER RESET AND FACTORY RESET...
The simple answer was put it into airplane mode. My phone was not on network so #*#* didnt work (code in other's post above). Gladly this was a half hour of this...
Side note: the battery was super draining so I kinda was suspicious of a radio like bluetooth or something being on but not notifying.

Putting the device in airplane mode cuts all network connections. Not sure if that's what the OP wanted.


text:
APK's AndroidManifest.xml looks to be binary
I'm not sure if this is a problem with my unzip tool, or not but I'm looking into the APK file structure and I see a file called AndroidManifest.xml. Inside that file there is no XML? It actually looks like a binary dump,
What does this file do, and should it look like this.
I'm using the official VLC nightly, I'm trying to troubleshoot this problem

https://nightlies.videolan.org/build/android-armv7/VLC-Android-3.0.11-20180618-0249-ARMv7.apk

It seems AndroidManifest.XML is a binary xml file, here is a tool to extract Binary XML. You can confirm that by using file
$ file AndroidManifest.xml
AndroidManifest.xml: Android binary XML

apktool can decode the binary XML format, and much more: https://ibotpeaches.github.io/Apktool/
It is available in many repositories, for instance on Ubuntu: apt install apktool

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.

Indeed, apktool decode app.apk works fine.


text:
How to disable Developer options on Moto E4 without clearing settings storage data?
In order to speed up my Moto E4 (Android 7.1.1), I followed this advice:
Settings > About phone > Build number (tapped about 3 times) which enabled Developer options. Then hit the back button >  Developer options.
One by one I opened three animation scales and brought them down to .5x:

Window animation
Transition animation
Animator duration

Then at the top of the screen I turned Developer Options off. However, it is still available now in my settings menu when previously it was not (before I hit "Build number" 3 times).
When I did this I didn't realize that I was opening a mode that wouldn't just close back when I was done. In searching for how to disable what I enabled, I read that I can disable developer options (remove it from the settings menu) by going to:
Settings > Apps > Settings > Storage > Clear Data
However, I am hesitant to do that because it says:
All this app's data will be deleted permanently.
This includes all files, settings, accounts, databases, etc

I'm not sure what files are included and how that will affect my phone.  It's only 700 kb though.
Is there another way that I can disable/close the Developer options that I inadvertently opened? If not, how can I know what the affect will be when I clear the settings storage data?
Thanks!

I just found an answer here that might apply to me but the build number is so much older and isn't the same device, so I will leave my question unless it is a confirmed duplicate.

after you have enabled developer options, and when in developer options, you get a toggle button to disable it. Otherwise, goto settings and clear cache and data of 'Settings ' application.

@RahulGopi Thank you. Yes, I mentioned that I did toggle to disable but that didn't remove it from settings.  I was asking if there was another way to remove it from settings without  clearing data of the settings application.

By doing above step, it will only affect settings app only. It doesn't affect with files, accounts, databases.

@RahulGopi that's what I needed to know. Now I'm thinking that I should reword my question so that someone else can benefit. The reason I was hesitant to follow the steps is because I thought that I would delete other stuff. Other people seem to be confused too.


text:
Does Xposed Framework require to be buillt specifically for the device or just the Android version?
When installing the Xposed framework do I need the device specific binary (like custom recovery or ROM) or just the app that works for Android (4.4.4 in my case). The device is Galaxy Tab E T560.

Update 12/7/2018

I tried to Install the framework as on the custom ROM as well as on the stock firmware but with no luck. It seems that Xposed is device/arch/firmware dependent.

To my knowledge, there are no device specific builds. It just needs to match the Android version. Worked that way for me on multiple devices for years.

Built for the Android version, plus the device architecture (arm/arm64/x86). See the Xposed Framework download page (e.g. Android 8.1 (SDK27) here).
The reason behind this is that part of Xposed Framework is a modified app_process binary (Zygote), which is different for each arch.

Hi! Thanks for the info.  I heard that you must find the correct one and flash it via twrp. I am also downloading many versions for my T560 (Lineage OS) and cannot install any xposed app with Unknown sources set to on.

If you're rooted then you can also use the Xposed Installer app which should automatically find and download the correct stuff for your Android version and arch. What you described sounds like another problem entirely.

I am getting this error: Xposed is not (yet) compatible with Android SDK version 19 or your processor arch. ( armeabi-v7a). CANNOT LINK EXECUTABLE: cannot link symbol "ZN7android14AndroidRuntime5startEPKcS2" referenced by "/data/data/de.robv.android.xposed.installer/cache/app_process". The device is also rooted with Chainfire SuperSU

@S4NNY1 Android 4.4? You'll need an ancient version (e.g. 2.6) of the installer.

Every damn version I try, the Install button is disabled and the error remains.

Then I have no more ideas. I don't have an Android device with Android version as low as 4.4 to test it out myself either...

Hi! Thanks for the effort. I'll try to somehow solve it and post the solution here it I find it. Thnak you again.

No problem, and please do, I'm also curious to see how it turns out.

It seems that it won't let ne install any XF on Linage OS.

I  have updated my post. I tried to Install Xposed on both custom and stock.


text:
How to view internal AND SD card storage on my Moto e4 when I connect it to my computer?
Up until a couple of hours ago I have been able to view my internal storage and SD storage on my phone when I connect it to my computer via USB. I simply swipe down on my phone, click USB for file transfer and select "transfer file." Since formatting the SD card I can view my SD card storage but NOT my internal. Should I still be able to see the internal storage after I do that?

Other than formatting the SD card, there are a few things that I did to my phone since being able to view internal storage:
1) I moved some apps to the SD card
2) I activated/enabled developer options (sorry I did that) but nothing is changed, that I know of
3) I cleared the settings storage cache (not data)
4) Some apps updated but I don't know which ones, I didn't pay attention to the notification
I'm not sure which, if any, of these things would cause me to no longer be able to view my internal storage.
I tried:

restarting my phone
unplugging and replugging the usb cable
restarting my computer (which also updated)
uninstalling the device driver (I did not get the checkbox option to delete driver but I did get this warning letting me know that I was uninstalling the device from my system and I continued with the uninstall)

Which OS are you running?

@xavier_fakerat Windows 8.1

I just updated my question and gave more information because now I am wondering if I am even supposed to see both the internal storage and the SD card if I formatted the SD card as internal storage.  I thought that I had viewed both storage locations after I formatted the card, but now I'm not so sure.

see: Access Adopted Storage SD Card via USB from PC - MAC - Computer

@xavier_fakerat That is the opposite of my problem. I CAN see my SD card, but not my internal storage. I included a picture in my question and tried to clarify my question.

Looks like your MTP drivers are corrupted. One way to resolve is uninstalling the driver and then reinstall it.
Depending on your OS running on your PC, locate the device manager and uninstall the driver:
If on Windows PC;

Go to Device Manager, expand Portable Devices and right click on your device.
Select Uninstall  (also tick the box besides Delete the driver software for this device) and click OK.

Unplug your device and restart your computer.
After the computer restarted, re-connect your device via usb and allow the MTP driver to be installed (it may take a while, so be patient)
When done check if the internal storage is  now visible.

There is no Portable Device folders. I included a picture of my device manager in my question for you to see.

It should only show when your device is connected. Did it not?

I guess I wasn't connected. I connected and I was able to see my device as in your picture but there was no option to check delete driver software. I clicked uninstall anyway and got a window that said: "You are about to uninstall this device from your system." I clicked ok.  And continued with your steps as directed. When I reconnected my device no MTP driver was installed. AMD catalyst control center opened though. I never saw that before. Was I supposed to do something?


text:
How to fix the problem of offline packages not downloading in Google Translate?
I'm having a problem with Google Translate and downloading offline packages for any language. I tap the download button next to the language, it says "Starting download" and the indicator is spinning, but nothing happens and the language pack is not downloaded. The app has the permission to use the storage.
My setup: the latest version of Google Translate (v5.20.0.RC10.199570264), on an Xperia L1 with Android 7. I should stress that with previous versions this used to work.
What I have tried:
1) Clearing cache and data of both the app and Google play (also the
    services).
2) Unistalling and reinstalling.
3) Rebooting.
4) Unistalling, rebooting and then reinstalling.
5) Moving the app to SD. Also the opposite.
6) Checking the permissions (everything is allowed).
7) All combinations of all of the above.
I'm about to try a factory reset, but before going nuclear I'd like to try some alternative.
Any hints/ideas are welcome!

The issue was solved by clearing the data of download manager as confirmed by OP .
Go to  Settings → Applications → Download manager → Clear data.
The download should proceed as normal.

This fixed my issues not only with the Google Translate app (which at least have some reasonable error code that brought me here), but also with the download functionality of the NPR One app which failed to download just some specific podcasts (which then appeared as incomplete in the downloads app). Thanks!

Solved turning off VPN... Never thought about this been an issue here.
Thanks for suggestions!

My problem was solved by turning off my Adguard VPN.

Uninstall Google Translation (with the memory card on your mobile).
Turn off  the mobile.
Remove the memory card.
Turn on  the mobile.
Install the Google Translation from PlayStore and give full permisions to application.
Install ALL the languages you want to use offline.
Turn off  the mobile phone.
Insert the memory card.
Turn on the mobile.
Copy the entire folder from the internal memory  Android\data\ com.google.android.apps.translate   to the exact same location on the memory card (if prompted, replace the same files that the memory card holds in the same slot).
Restart the mobile.
Now everything in  Google translation works well.

Never mind, it was because no space in sdcard !!

I had this problem too. I changed wifi to cellular data . It solved!! Google couldn't downlad via wifi

Google translate offline the audio doesn'twork when you're trying  to imput using audio ....the microphones is  blanked out
and also the output there no audio ...... input is English and the output is Vietnamese I downloaded the file no problem
You can try to import in and afterwards you can get audio on the input but not on the output


text:
how to exit developer mode on android 4.0 ice cream sandwich
I have a Sony-Ericsson Xperia Arc S with android 4.0,
the dev mode was activated by mistake by a non tech person.
( so now every touch/drag draws a line, and on the top it shows x,y coordinates )
I can't find how to disable it

If you just want that line / coordinate overlay gone, disable Settings - Developer Options - Pointer location.

To Disable Developer mode goto settings-> developer{ } then there is a slider on  top of Developer options which you can on/off.

for me it's only Settings -> Developer Options and inside there's no slider only grouped checkboxes,   "user interface" ( Strict mode enabled, pointer location, show touches ... ) ... "Apps" ( Don't keep activities, Background all ANRs, Show all ANRs)

@Omu I do wonder why it is so, I remembered that Android 4.0/4.1 devices do have a global toggle controlling Dev Options on the top bar, and Sony did very few UI changes so they shouldn't have touched it.


text:
How to print from a browser in an android device
So, here is the situation: We are a SaaS company, our contractor haves multiple Zebra phones and Zebra printers, they want their salesman to be able to go to the place where they sell their stuff (they are product providers), and make an invoice in their phone, then print it and give it to the person in charge of the place.
I want to be able to print the invoice from the browser (since our software is a web app), the printer is attached to the android device with Bluetooth, there can't be any dependence to computers (so I guess I can't use Google Cloud Print) and it shouldn't be a long process, it should be efficient.
I also can't pay for printing apps, I downloaded lots of them and either they don't work, or they ask you to pay after certain amount of prints, if it's needed, we can develop an application to connect the printer with the browser.
Printer: Zebra iMZ320.
Android version: 7.1.2 (Nougat).
The browser they use will be variable, we can't develop something just for certain browser, it must print from ANY modern browser.
Thank you in advance.

Bluetooth printing isn't something native to Android, in this case Bluetooth is used only to "help" your device connect to the printer via the network or WiFi Direct... I suggest you contact Zebra to see if they have Android printing support.

Zebra does have its own printer app, though it seems they've abandoned it (no updates for 3 years) – or replaced it by this app. Have you tried one of them?


text:
What is CCleaner for Android referring to by "Hidden Cache"?
CCleaner for Android cleans regular cache and "hidden" cache.
What do they mean by "hidden" cache?

Other apps mention that as well, e.g. the cleaners of Avast and AVG – so it seems this isn't specific to the app. I would guess they refer to the apps' "private cache" (i.e. a cache directory inside the apps' private space in /data/data/<package_name>).
This developer article might give some insight. Quoting (emphasis mine):

By default, Android Extensions adds a hidden cache function and a storage field to each container (Activity, Fragment, View or a LayoutContainer implementation) written in Kotlin. The method is pretty small so it does not increase the size of APK much.

Another insight from our sister site:

… but other then that it's all saved on hidden cache partition.

Which suggests there's some special hidden cache partition somewhere – or the writer of that answer got it a bit wrong (which I think is the case).
A third variant: Some apps create "hidden cache folders" on the SD card. Now guess what "hidden" means here? sdcard/Android/data/<some_app>/.cache – a hidden directory (leading dot in the name) called .cache.
No straight answer, sorry – but my guess is it's referring either to the first or to the last of these 3 options. Highest likelyness is the latter – which seems to be confirmed by the SD Maid wiki¹:

"Hidden caches" targets cache like files that are in non-default cache directories, e.g. videoCache, .cache.

One thing for sure: they're NOT talking about geo-caching with that

¹ thanks to SSS for this pointer!

From the SD Maid wiki, it seems to be variant 3. Ran it on my device, interestingly it also caught APKs from Aptoide under the /sdcard/.aptoide/apks folder. The folder's size is much bigger than the Aptoide size shown in Android app info, meaning that it is a special folder and clearing the cache, data, or uninstalling the Android app might not make the "Hidden Cache" go away (hence the use of the Cleaner).

Good pointer, @SSS – that was my strongest guess as well, just found no literal proof. Will integrate that with my answer.


text:
Lost Phone - Enable Secure Erase
So I lost my device today and it was a Samsung Galaxy Prime. I went onto Google's "Find my device" and there were only 2 options: "Start ringing" and "Enable Secure Erase."
I pressed the Secure Erase button, then I searched online for what that meant. It turns out that it will wipe all of my data away. I wanted to undo that option but it turns out I can't.
So will all of my data be erased and will I be able to get all of my data back?

Please update us if you were able to find your phone!

The “enable secure erase” button does not actually erase your device. Instead, what it does is reach out to the device to and turn on the Device Admin permission for the Find My Device app. So if that's all you've done, your data is still fine, and you can undo it by going into settings and removing Device Admin permission. Despite that, I'd still go with acejavelin's paranoid approach if I had any un-backed-up data.
After you press "enable secure erase", Google contacts your device to enable the feature (not erase your device) and once Google gets an answer back, you should see two new buttons — "lock device" and "erase device". If you then hit "erase device", your device will be erased. And since it was probably online (otherwise the two buttons wouldn't have appeared), it's very likely too late — the device has already been erased.
Google does make it very clear what this button does:

Unless you pressed that button, you should be fine — but again, there is no harm in following acejavelin's paranoid procedure, so I recommend being paranoid!

I had to assume the command had been issued... Better safe than sorry. :)

@acejavelin Understandable, and I hope I've emphasized enough that I recommend the OP follow your just-in-case guide.

Since you have already initiated the Erase procedure, the only solution is to prevent the device from contacting Google so the wipe command to Find My Device (the Google Device Administrator service on your phone) is not received or executed. Once the erase is initiated from the website the command will go out, it cannot be stopped from happening, although it can sometimes be mitigated.
Assuming you find the device and it is powered off or the battery is dead, DO NOT attempt to turn the device on. Remove the SIM card and disable any WiFi that may be in range device, such as turning off your wireless router and any network it may automatically connect to, if it connects to the Internet and Google, it will wipe all data immediately.
Once you have removed the SIM and disabled WiFi, power on the device. As soon as you are able to do so, turn on Airplane Mode. Then go to Settings - Security - Device Administrators and disable Find My Device's administration capabilities. Important things here are usually photos and video in the DCIM folder.
Now backup any data via USB to PC, SD card, or OTG flash drive. Do not attempt to backup to any cloud service, install apps, or anything else requiring network access.
Verify again that Find My Device does NOT have permissions as device administrator by going to Settings - Security - Device Administrators.
Now enable the network access (WiFi or reinstall SIM) and verify you can access the Internet and your Google account such as Gmail, and continue to use the device for a few minutes. I would suggest backing up anything you needed an app or the cloud to backup that you couldn't earlier, such as text messages via SMS Backup & Restore app.
Now reboot, and make sure everything is working as expected. After 5-10 minutes, go back to Settings - Security - Device Administrators and authorize Find My Device again.
In many cases the wipe event has "passed" and the device will not reset, but in some instances it still does occur. Either way, realize it could still happen, but if it goes 24 hours the wipe event most likely will not occur.
Also note that if it does get wiped, you must log back into the device using the same Google account and credentials that were on the device previously as it will likely be in Factory Reset Protection (FRP) mode.
There are a few articles, mostly dated, on the Internet regarding this, most are fluff so be careful... This answer is largely paraphrased from this one which I have used before.
BTW, next time something like this happens... Research on the Internet first, then press the Doom and Gloom button after you know what it will do, not before. :)

THANK YOU SO MUCHHHHH!!!! I've been worrying a lot for the pass few hours and I couldn't concentrate on my studies with my phone getting lost. This is super helpful and if I hopefully find my phone then I'll will carefully follow these steps. I am forever grateful for your reply! :)


text:
Drop\stop mobile data connection (non-wifi) by conditions
Can I set Android 4.4.2 to drop mobile data connection once a data limit set by me is reach within a period?
Which version of Android has this feature?
How can I achieve this?

That's already been answered in detail (much more details than your short one-liner) at e.g. How to control, monitor and limit bandwidth usage?. And this feature was introduced with Android 4 aka ICS aka Ice Cream Sandwich.

@pop if you're comfortable with third party apps you could try 3g watchdog which allows you to set custom periods like 1 day, week etc then switch off mobile data altogether...

Settings only available after you turn on mobile data, it's under settings-->data usage.


text:
Why some of the android apps doesn't work on Wifi
Why some of my android apps doesn't work on Wifi when all other apps work fine.
And these apps work on Mobile Data but not on my Home wifi.

These apps work when I switch 'Airplane Mode - On' and turn On my Wifi

Tried:

Have tried searching this on XDA forum
Tried Static IP instead of DHCP
Setting my time and date manually
Checked my App Data Usage (for specific app) - 1.66Mb over Wifi & 11.02Mb over Mobile data
Tried my Wifi password twice, tried rebooting my phone twice.
Tried App Restrictions & Storage Permissions
Turned Power Saving Mode - Off

FYI:
My app is in Testing phase - Loading Bitmaps
My Phone is Coolpad3600I ver: 6.0.1
Couldn't understand this weird problem. Need help.

Didi you check the Logcat and troubleshoot the app?

Thanks @esQmo_ I forgot to mention, when I tested it on other phone Huawei 4.4.2 wifi was working fine, and it was loading the bitmaps as expected. Logcat was showing lot of messages since I was using Firebase to load bitmaps, nothing was shown which was wifi or data related - so I was quite sure, the problem is device specific.

After a lot of research yesterday, I found my project was lacking few crucial steps for loading bitmaps

Caching of bitmaps was not properly implemented because of which I was getting Out of Memory errors
I was also getting Android Support Disable plugin error after every few minutes
Android Profile Analyzer was showing lot of irrelevant threads which was consuming memory

Since, I didn't have much time to look in every file of my code. I modified my sluggish code and imported Android Bitmap Sample code from the library.
Most of the common errors of Wifi, caching of bitmaps & Disable Plugin errors were taken care.


text:
Unknown popup message with a text input, "cancel" and "send" buttons, but without notification entry
Recently I received multiple popups that looks like this:

The popup has a high priority since I can't do any other thing when the popup is displayed.  It also doesn't appear in the notification.  When I click "Cancel", the popup disappears immediately.
I'm running Android Oreo 8.1 with the latest security patch.  The message looks like an advertisement sent from the operator.  I've tried to disable all emergency alert (from Wireless alerts menu in Google's SMS application setting), but the message still appears.
I would like to know what kind of popup is this (doesn't look like from an app) and what would have triggered it.

This is similar to messages that displayed when we type USSD codes. Possibly its from the service provider.

Is it possible for service provider to trigger USSD in my phone without my consent?

Related: How to prevent phone operator from opening spam popups? and How do I block this (carrier) advertisement dialog?

Have you found the solution? I got this a lot from Indosat. Contacted their CS and have tried all of their advise but nothing works.

@AndrewT. This is different than usual flash SMS because it has an option to reply (with Send button).   Usually just have "Save" or "Discard" button.  I think How can we send a flash SMS with reply option? is trying to send something that looks like this.

No, @ThariqNugrohotomo, I still don't know what is this.


text:
Android device doesn't support Google Play Services
I'm using Samsung Galaxy Trend 3 SM-G3502U on Android 4.2.2.
Since this is a Chinese device, so it was normal to be shipped without GApps. So, I tried to install the latest version among the versions which are compatible with Android 4.2.2 of the following apps from APKMirror:

Google Play Services
Google Play Services Framework
Google Calendar Sync
Google Contacts Sync
Google Account Manager

Still, no luck, since when I tried logging into Snapchat, a pop-up "popped" out, saying that Google Play Services is not supported by my device.
Also, when I installed and opened the latest version of Play Store among the compatible versions for Android 4.4.2 from APKMirror, it showed "Error retrieving information from server RH-01" which meant that I didn't have the compatible GApps installed.
Having all the apps listed above installed, I installed the "Device ID" app by Evozi. It couldn't show me the GSF. The space for that was left out empty instead.
Now, are there any more ways to try out for me so that my phone supports Google Services Framework, or I am left out with installing a custom ROM?

First, I wonder how those apps should work when installed as user apps, as several (if not all) of them require elevated permissions and thus must be installed as system apps. See e.g. How can I install the Google Apps Package (Play Store, …) on my Android device? OpenGApps might be worth a check as well, but make sure to read their FAQ.

I cannot find my android version on OpenGApps (4.2.2). So, will I have to install a custom rom?

Although I found one here: https://www.google.com/amp/s/boycracked.com/2017/05/24/official-gapps-for-android-4-2-2-jellybean-flashable-zip/amp/  it requires me to flash a custom recovery, for which I have to unlock the bootloader. But I'm not being able to find a suitable version of Odin for my device to do this. And also, some other tutorials do not guarantee their method for all samsung devices, like the one here:https://www.quora.com/How-do-I-unlock-bootloaders-on-Samsung-phones# . And most importantly, I cant find my device in the TWRP devices list

Sorry, but Android 4.2.2 (Jelly Bean) is ancient (2012/2013). The latest version is Android 8.1 currently, so you won't find much support for something that outdated (though you can check our google-apps tag-wiki for some viable alternatives – and indeed, TeamAndroid has some for 4.2). And yes, to flash 3rd party stuff (Custom ROM) you'll need a custom recovery, which needs an unlocked bootloader.

Jelly bean Android devices are still supported by Google Play Services https://en.m.wikipedia.org/wiki/Android_Jelly_Bean

If possible, check out the microg project https://microg.org/

The apks will not work without system libraries, and other frameworks that cannot be installed without root (or flushing from a recovery).


text:
"Install overnight" option does not apply update over night
When an update to the android is available, there are three options what to do with it:

Install now
Install overnight
Later

When I select "Install overnight", the notification bar says: "Update will be installed between 2 AM and 5 AM automatically." However, next morning, nothing is installed.
What's the problem here, can't the phone read the clock? How can I fix it to enable the automatic installation overnight?

Android 7.0
Samsung Galaxy XCover 4

If it is a security update, there wont have any change in UI. please check for any change in android security patch level in settings. If its an OS update, then there will have some UI change.

Are you sure your software did not update?
Try to check it.
Open Settings-About Phone-Software Information
Check Security Software Version and Android Security Patch Level as well.
In Security Software Version, month of installed software is mentioned.
Why software not updated overnight ?
Well, this may be due to these possible reasons:
• Your device battery was running low that time.
• You have enabled any type of battery saver.


text:
How can I use a bluetooth controller to skip back/forward a video 5/10 seconds?
I've been trying to find an application that will skip a video backwards 5/10 seconds when I press a button on a bluetooth remote and maybe even save a bookmark to a list of bookmarks when I double click for instance play. I was able to do this on a rooted ios device using an app that remapped the forward/next track keys to short skip. I'm watching video lectures and want to control the playback. Is there any hack that will allow this in for instance VLC which already short skips when double tapping the side of the screen?

MX player has this functionality although it doesn't appear to have a bookmarking capability that can save multiple bookmarks in a video.


text:
Access Android SD from Windows 7 via card reader
I want to backup my sd-card, before using it in my new phone. So I used a card reader to connect it to my Windows 7 notebook. Sadly the partition is not mounted to a drive letter, altough I can see it to be free of errors in the disk management.

I suspect android uses an unsupported file system. But which and how can I read it from Windows?
EDIT: My phone is a Moto G3. The device is not rooted. The SD was formatted and mounted by the default Android-dialog for new SDs. I did no customization. I'm using a part of the SD card as internal storage.
Thanks for your support,
nils-o-mat

You could use adb shell or any terminal app to find out. Simply execute the command mount without any parameters. Seeing 2 partitions on the card suggests manual adjustments: Are you using Link2SD, or have split the card to use partially for [tag:adoptable-storage]?

Thanks for your comment. I will try to get on the shell to find out. I edited my question to clarify, how this SD-format was created.

Thanks for clarification! What you forgot was to tell whether you're using parts of that card as "internal storage". If that's the case, you won't have any luck reading that partition via a card reader as it's encrypted.

In fact I do. That may be the problem than. Tank you!

The fact of using your SD card as internal storage explains your problem: partitions for adoptable storage are encrypted, so on your computer you can only see the partition but not actually read its contents, as you lack the encryption key (for details, see: How to decrypt Adopted Storage?).
As you wrote you did no customization I'm wondering why there are 2 partitions on the card – and according to the screenshot, none of them reveals the file system used. By that fact (not showing the file system) I'd assume the second partition is encrypted as well.
As for the file system: Android normally uses some FAT style file system on SD cards. But if adopted, it's rather a Unix file system, most likely ExtFS (ext3 or ext4). Again something Windows cannot deal with unless you install specific software. If you want to know, use a terminal app or adb shell, and run the command mount. Watch out for the entries of your SD card there, then look at the file system column.

Sorry, but my reputation does not currently allow me to upvote you.

No prob. More important is it helped you – and you marked it such for others in a similar situation. Thanks for accepting my answer!


text:
How to remove persistent "Mi Band is Connected" notification in Android?
I have Mi band 2 from Xiaomi, always connected to my Android device for fitness activity tracking. In the notification drawer, there is always a persistent(unclearable notification) - "Mi Band is/isn't connected - which is annoying. Is there any way I could make it disappear and receive other notifications from the Mi Fit App, if any?

Do you have the right to move this question to move there?

Profile -> Settings -> Show Status in Notification Shade

August 2018
Android version 8.0
MiFit App version 3.4.4

Just to note, I used this to "fix" an annoying feature of Mii Fit, where there was ALWAYS a badge on the icon, to show a notification.  Obviously the notification was that the band was connected, but it was driving me mad trying to clear the number and make my home screen "clean".

As I remember, in Mi Fit application at the Profile -> My Devices -> Mi Band 2 exist special option for this notification.
Unfortunatelly, right now I'm using Mi Fit at IOS and cannot check it, but earlier I switched this notification off, if I am not mistaken.

No, there is no such option under the devices option.

It is there :) Check: Status -> Setup -> Show status ....

Please mention the full location of the option. Thanks.


text:
How can schedule an event that doesn't start on 00, 15, 30, or 45 on Microsoft Outlook for Android?
How can schedule an event that doesn't start on 00, 15, 30, or 45 on Microsoft Outlook for Android?
For example, I would like to schedule an event that starts at 14:08, but when I drag and drop the event, the start is always on 00, 15, 30, or 45:

On your screenshot, the top row of "choose time" go to the far right. You will see up and down arrows with 00:00 in between. Select that and you then will be able to enter a specific time.


text:
Is it possible for the application to execute some code installation time?
Just installed the application X. I never opened it.
Is it possible for X to make some actions (execute some code) installation time, even though I never opened it.
In Windows when you install the app many things may be done. But Android is another beast.

Did you know that apps can be triggered by broadcasts even if they don't have an UI (i.e. can't be "opened")? It doesn't happen at install time, but it still qualifies as "executing stuff while you never opened it".

I am familiar with the concept of service https://developer.android.com/guide/components/services in Android, and yes @AndyYan it has lot of sense that app X which I am using in the question may have services. I am not sure if these services may be activated even before I open the app for the first time.


text:
Allow enabling of screen after timeout
I want to allow waking up of the screen either through using the home button or from a screen swipe or a tap on the screen BUT the screen should only wake up after a delay of say 5 seconds.  For example, here is the sequence of events:

screen has gone to sleep
user presses home button (or swipes or taps, whatever is easiest to wake up).
but the screen will not wake up until a set time delay has elapsed.
After time delay has elapsed instant reenabling of the screen is enabled.

Is there a setting or an app for this?


text:
How can I use gmail mobile without having to sync
I have a school google account that does not allow sync.
I have just added it to my Android phone and set up gmail, however when I try and get onto the account it asks to sync.
As sync is disabled the sync button will not work. The 3 line setting button just displays Waiting for Sync.
How do I use GMAil on my phone?
I cannot install any other apps since the phone only has 200mb due to the fact that it is a cheap Samsung.

Does it work if you disable syncing gmail from your devices settings? Should be under accounts then select google. Next, select your account if multiple accounts are on the device. Then go down to gmail and un-tick the selector.


text:
How to fix ADB logcat error?
I want to save logs contains to file:
adb -s xxxxxx logcat -b main > /paths/to/log/file.log

/system/bin/sh: can't create /home/dpi/Desktop/Folder/main.log: No
  such file or directory

What operating system are you using on your computer?

ubuntu 14.04. I write an app that calls the process "adb ...."

I believe your format might be off on the adb command. On linux after the
> ~/Desktop/Folder/main.log where as windows is

%userprofile%\desktop\logcat.txt as far far as coding I do not know if there is a universal one but adb commands I am familiar with.

I tried with gnome-terminal "adb -s e15a154d logcat -b main > /home/dpi/Desktop/Folder/main.log". This is OK, but in my app got this error.

As for coding your app the sister site might be a better place to ask this question https://stackoverflow.com there is this though: https://stackoverflow.com/questions/23807689/catch-logcat-programmatically-or-export-it-to-file

What happens if you try to pull the logs through a shell instead. Something like adb -s e15a154d shell logcat -b main > /home/dpi/Desktop/Folder/main.log

the problem is /system/bin/sh, shell is called from android phone instead of OS

I resolved this problem. tks so much!


text:
Switch Chrome interface between smartphone mode and tablet mode
I want to change the interface of Chrome on my Mediapad T2 7.0 Pro (PLE-701L). Now it looks like the smartphone version (picture at right side):

But I want to change the interface to tablet mode (picture at left).
As I know there is a special command for switching the interface.
Config:

Tablet: Mediapad T2 7.0 Pro (PLE-701L)
Resolution: 1200x1920
OS: Lolipop (5.1.1)
UI: EMUI 3.1
Chrome: 66.0.3359.158
Root: doesn't exist.

You will need to change the DPI of your phone to accomplish it. But, the change will affect the whole system not just Chrome and may not be retained after a restart due to your device not been rooted.
adb shell wm density 600 (When I tested, 600 was the value that enabled the change of interface in Chrome).
For those who have newer version of Android, the DPI can be changed by going to Settings -> System -> Developer Option -> Smallest width.
Chrome's interface will change from phone to tablet.

didnt work for me. Even on 700, still Phone-mode in Chrome :(

I can confirm that for Android 7 on my TAB S2, that changing: Settings -> Developer Options -> Minimum Width, to anything below 600 activates "phone" mode. Anything equal to or above 600 activates "tablet" mode. Setting sticks between reboots.

I started with minimum width 600, it did activate tablet mode for Google Chrome on my Google pixel 7. It made the font smaller than I liked So I started messing with the minimum width... As info, the default setting was 411... The closest I was able to get and still have tablet mode in Google Chrome is 476. Thank you guys so much!


text:
How do I stop others from remotely controlling my phone
Other people are remotely controlling my phone. How do I stop them and get my life back?
Sometimes I will see the screen being navigated when I am not even touching the phone. Swiping motions, back button presses and menu selections happening automatically without my finger even touching the phone or my voice interacting with Google Assistant.

What do you mean by remotely controlling? Please clarify what is happening

Could you add detail such as : your phone model, is it rooted, and what software have you installed recently? It's hard to make a specific answer without these details.

@esQmo_ sometimes my screen is being navigated by somebody else's finger. Maybe it's a ghost that I don't see in front of my face? Probably not. Most likely somebody else is navigating through my phone remotely.

@Zackary we are using the Moto E4. The updates are current. We are only using apps that came with the phone and a few other big-name apps that are very common. The phone is not rooted, was purchased directly from Verizon and has been on the same Verizon service the whole time. The phone came with Android 7.1.1 and it is still running Android 7.1.1 with Motorola updates.

Are they doing specific actions? (I mean those you think are hacking yout device),  such as accessing your infos: SMS, call history, social networks activities... Or the "touch" seems randomly? Eg an area being touched whatever screen you are at at the moment?

@esQmo sometimes I try to make a call and somebody else is already on the line.  They appear to be impersonating me and my wife or simply jumping on our cellular connection so they don't have to pay for one

Is this even possible with a cell phone? I doubt but who knows... ?

Yes it is possible.  You can either believe me or do more research on the internet.  We have had this experience.

Have you turned on developer mode ?

@ArjunVK No I do not use developer mode and have not turned it on. I develop on my PC and through a secure and private Google Play channel without ever using developer mode on my Android device.

It's a really broad question but this could solve any remote control issues.

(try this method first):

Force power off your phone (hold down the power button until the screen does black)
Turn off your Wi-Fi, and remove any SIM cards.
Power on the phone.
Look in the Downloaded folder for any suspicious software (such as com.google.daemon or "Service of Google Play") and remove it (if there is only an "Uninstall updates" button, then it is real system software).
Power it off, turn on your Wi-Fi, insert your SIM card(s), and tun it back on.

(only try if #1 didn't work):

Turn your phone off, and put it in recovery mode (can't say exactly how without your phone model). Navigate to wipe data/factory reset > Yes - erase all data (WARNING: you will lose all data on the phone).
Turn it back on. It should be fixed unless the R.A.T (stands for Remote Administration Tool or Remote Access Trojan) is a system app.

Yes, we have done some things like you have suggested

There is some DM apps on the phone by default.  Also some strange VPN apps.  We have tried to disable them, but the list of 150 unusual apps is so long and convoluded that we havn't been able to solve the issue.  We don't have the R.A.T. but there are various other apps that may be producing similar results.

What we have done to some success is remove our account from the android phone and stop using many apps that have more advanced functionality.  We have seen some success at being able to make and receive phones calls a little better.  We are getting text messages sent from us and to us that we never wrote and the other person never wrote.

@EeshwarDas You could root your device and install an app that can remove system apps (like Titanium Backup) to remove those apps. Be careful what you remove, though - system-independent apps are OK to remove, but system apps could soft-brick your phone (it can be recovered from that, but it requires the stock ROM and an understanding of fastboot).

Hey Zackary, the at function is not letting me shout to you.  Maybe something wrong with Stack Exchange in my region.  Yes, I could root the device, but my understanding of being an Android Device Admin is not sufficient enough to get past this significant amount of Malware on my first try rooting a device.  I would definitely ruin the device if I did what you say.  It would be possible to learn, but I don't have the time or the money.  There are many apps posing as system apps that are clearly not system apps, so it would take an Android surgeon to be able to fix this device.

Download an app calldd 0permission and verify your kernel module is correct.
Exposing a bootloaderand rooting is in the past.
People like to expose your initrd
(initial ramdisk) and backdoor their shell command off that

user332372, why a new app? Shouldn't Google simply prevent this issue without any need for third party apps?

these ghost touches are a well known hardware failure of touch screen. replace the digitizer or whole screen

https://www.androidpit.com/how-to-fix-the-ghost-touch-problem-on-any-android-device

alecxs, good suggestion, but in my case I have seen enough proof that this issue was due to malware. The hardware worked very good on my device.


text:
Cannot change mobile network Sony Xperia V
I have a Xperia V device which worked fine until few days ago. I still use 3G SIM, and I've enabled WCDMA(preffered)/GSM from settings menu (Settings->More>Mobile Networks->Network Mode). This works perfectly fine until few days ago. I usually get 3G signal, rarely 2G.
One day suddenly I found that phone with no mobile network connection. I thought maybe something wrong with signal coverage. But it didn't changed even after I changed my location. I has few options in Network Mode menu as follows,

WCDMA only
GSM only
WCDMA(preffered)/GSM
LTE(preffered)WCDMA//GSM

If I choose anything with WCDMA, phone gets disconnected from the carrier and I can only use the option GSM only whyich gets the connection.
I haven't updated or rooted or did anything to the phone recently.
I tried restarting the phone, toggle flight mode , remove and re-insert the sim card but nothing works.

Why can't I connect to WCDMA/3G?
Why am I only able to connect to 2G network?

This happens in every scenario.not on when turn on mobile data connection. I lost signal when I try to connect to any option other than GSM only

Verify that the APN settings (in mobile networks) is correct with the carrier.

@Bo Lawson, What the APN settings have to do with signal lost? Or what setting OP need to check ?

@esQmo_ Really just a step in troubleshooting data issues. I was thinking it had to do with the loss of 3g and only being able to access 2g networks. Maybe the carrier changed them and his phone did not get the updated APN.

@BoLawson It's not related to mobile data connection, but no mobile network connectivity. How can I fix that?

Maybe the settings of changing network are not sticking as they should. Try lower level stuff as explained here https://android.stackexchange.com/a/189727/131553

@beeshyams same output happens. when I choose WCDMA only, signals get dropped. same as above. I don't know what to do now

Only thing I can suggest is to take backup, factory reset and flash your ROM or the updated version. If that doesn't help, head to service center

@beeshyams are you suggesting that this could be a hardware problem?

Suggesting a way to trouble shoot. If first part of suggestion works, fine else it may well be hardware

Also check the network operators in /settings/mobile data/settings/mobile networks/network operators. Next, try to manually set the network with search network then select the proper network I.E. t-mobile wcdma or whatever.

@BoLawson when I try that, I can see both 2G and 3G networks available on my carrier, but when I try to register on 3G network, it displays an error message saying unable to register, make sure sim is inserted and supports the selected network


text:
Clockwork Mod tether stopped working recently
I am using moto g4 and windows 10. The symptom is: when starting the windows app and clicking start button, the application starts normally: the log windows fills up and the button changes to "stop". After a few seconds, thou, the wording on the button changes back to "start", the log stops updating, and there is not connection
Anyone else experienced this? any quick fixes?

It might have being a problem with my USB cable. I tried again with a new one and now it works just fine. highly recommended app


text:
Samsung Galaxy J7 Pro 2017 (SM-J730GM) doesn't seem to support partitioned SD cards
I have a Samsung Galaxy J7 Pro SM-J730GM purchased at a Sanborns shop in Mexico, running Telcel's stock ROM, rooted, with TWRP recovery and Link2SD. A couple weeks ago I repartitioned my SD card in order to use Link2SD's app linking function. I remember having to reboot my phone a couple times before it picked up the card, but at the moment I thought it had finally worked. However, apparently it was just a fluke, because today I restarted my phone in order to flash TWRP, and when I started my phone back it didn't detect the card anymore.
The card is fine, as it can be read with no problems on a PC running Linux. The card reader is fine too, as the card is legible from TWRP and can be formatted without a hitch from Android. With that in mind, I tried formatting the card using my device's Set Up function, then I repartitioned it with my computer. When I inserted the repartitioned card, that's where my phone began refusing to mount it.
Has anyone had any luck mounting a partitioned SD card on this model? Am I going to have to flash an aftermarket ROM into my phone?
(PS: I'm going to try to reproduce it with a different card)

What format's did you make the partition's?

Partition 1 is FAT32, partition 2 is Ext3.


text:
DB of GPS Point in APK, is there any way?
I want to extract DB of GPS location in APK. I decompiled the APK and open DBM.Java File as follows:
   public DBM open() {
    return open(this.databasePath);
}

public DBM open(String path) {
    try {
        if (!path.endsWith(SQLITE_EXTENTION) && SamaUtils.absoluteFileExist(AppViewer.getContext(), path + SQLITE_EXTENTION)) {
            path = path + SQLITE_EXTENTION;
        }
        this.portalDB = SQLiteDatabase.openDatabase(path, null, 268435456);
        return this;
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

How I can extract the DB of GPS Location in this APK?

The excerpt of decompiled code you've pasted isn't sufficient to know the exact path to the database, because it doesn't give the value of this.databasePath, but no matter. The file will be stored somewhere in the app's private data, so after you've rooted your phone, just look in /data/data/packagename where packagename is the package name of this app. There will be an SQLite database file in there somewhere. The constant SQLITE_EXTENTION in the code you've decompiled but not included will tell you the extension to look for: it's probably .sqlite_db.
Don't forget you'll need a rooted phone to access the file.


text:
How to configure bluebooth dialing behavoir?
I connect a Bluetooth earpiece to my Android phone to allow me to receive calls when driving. By accident, I discovered that if I quickly press the button on my earpiece twice, the phone will automatically re-dials the last outgoing call, which is pretty annoying.

Is this a function of the Bluetooth earpiece, or a function of the phone?
Assuming that it is a function of the phone, how can I configure it so that it re-dials the last call, irrespective of whether it is incoming or outgoing?
I cannot find this function described anywhere in the manuals that come with either the Bluetooth earpiece or the phone. Where can I find more hidden functions where clicking the earpiece button at a predetermined pattern will make the phone do something?

My phone is a Asus Zenfone if it matters.

It must be the feature of that bluetooth earphone


text:
I used Google Takeout, how do I remove this data?
Google Chrome Bookmarks, extensions and history. I don't use chrome anymore.
Google Play library, I cleared it in google play but the installs.json and library.json are still huge and contain uninstalled apps.
And lastly all Google Play reviews I did.
(This is not off-topic, since it is about google play and chrome)

That's rather not an Android related question. If you're European, you could refer to the GDPR and demand deletion from Google.

I do not want to remove my account, just that data. The Right to be forgotten removes everything

I didn't say demand account deletion. And I'm not talking about the "right to be (completely) forgotten". I'm talking GDPR's right to erasure which replaced that. Quoting from the Wikipedia article: "Article 17 provides that the data subject has the right to request erasure of personal data related to them on any one of a number of grounds". For details, see e.g. here.

There's nothing much we can do except giving you a pointer: if you're an European citizen, GDPR article 17 gives you the right to demand erasure of your personal data. Quoting from paragraph 1:

The data subject shall have the right to obtain from the controller the erasure of personal data concerning him or her without undue delay and the controller shall have the obligation to erase personal data without undue delay …

After that, a list of conditions follows. For your case, the very first one (a) should apply:

the personal data are no longer necessary in relation to the purposes for which they were collected or otherwise processed;

Some of the others might as well.
Summing up: if you want those data erased, you should reach out to Google demanding erasure according to Article 17 GDPR. To my knowledge, "without undue delay" is interpreted "ASAP" with a cap of maximum 30 days.


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Backup strategy for non-rooted phone
With apologies for my naivete:
I want, insofar as possible, to periodically back up the data on my non-rooted Samsung Galaxy S8.  To this end I do two things:
1)  I periodically do adb backups with the command

adb backup -all -apk -shared -f backupfile

2)  I mount my phone as a network drive on my Windows machine, where I use robocopy to maintain mirrors of the directories /sdcard and /storage/0000-0000.  These mirrors are updated nightly via a script containing the commands

robocopy z:\sdcard d:\phone /s /z /zb /mir /xx /xo /fft  /r:0 /w:0 /min:10

robocopy z:\storage\0000-0000 d:\phone /s /z /zb /mir /xx /xo /xd mp3s /fft /r:0 /w:0 /min:10

Thanks to Izzy's very helpful answer here, I am aware that some apps store data in directories such as /data/data that are not accessible to me without root access, and also that some apps might have opted out of making their data accessible to the adb backup.
Question 1:  To clarify:  Is the adb backup (at least potentially) capturing at least some data beyond what I'm able to capture in my mirrors?
Question 2:  Is the adb backup restricted to data that has been created by apps?  For example, if I've manually copied a file from my computer to my phone's SD card, is that file included in the adb backup?
Question 3:  Does any of the above strike you as insane, and if so, what strategy would be saner (short of rooting, which I prefer to avoid)?

Most of your questions are already answered on our site. May I suggest you take a look into our backup tag-wiki and Full Backup of non-rooted devices?

"mount my phone as a network drive" Could you please share how you achieved this?
I have been googling, but haven't yet stumbled on the correct incantation.
I'm not sure what directory to point Powershell, since it doesn't seem to be able to see the phone.

I did this long ago, and this is from memory, so I can't guarantee it's accurate.  But:  Since you mention Powershell, I assume you are using Windows.  Step I:  install WebDavServer on your phone from the App store.  Step II: Start the webdav server, and it will tell you your phone's IP address.  Step III:  From left column of Windows file manager, right-click "This PC" and choose "Add a Network Drive".  This will let you enter your phone's IP address and assign it a drive letter.  With the WebDav server turned on in your phone, the computer will usually see the phone as a drive with the (CTD)

(CTD) assigned letter.  Sometimes (apparently randomly) the computer fails to see the phone, in which case you can look in the left column of File Manager, look for the network drive you created and click it a couple of times or something until the computer figures out what you're trying to do.  Now you can just type "Z:" (or whatever letter you assigned) in your command window and use your phone as a hard drive.

Thanks for sharing that - I will give WebDavServer app a try!

@m1m1k :  Just in case this trips you up:  You need to choose between "map network drive" and "add network location" from the file manager dropdown.  I am pretty sure you want the former and very sure that you need to make the right choice.


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When I remove a payment profile, will I still be able do install my purchased apps?
I purchased a few apps a few years ago, and my credit card expired a long time ago. So, if I close my payment profile on Google Play, will I still be able to install the apps I purchased?

Would just removing the card from your profile be satisfactory as opposed to closing the entire profile?

It appears you are confusing payment method with payment profile

If you close your payment profile then you can't install earlier purchased apps as explained in Google payments center help

When you close this profile, the service(s) below will be canceled:

Google Play Apps

YouTube

Google Play Movies

Instead, Add, edit, or remove a payment method

I have had an issue with changing the Google Play country and they recommended to delete the past payment profiles. I have enquired about the past purchases and they said (twice) that I will not lose them.

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.


text:
Is it possible to view Google reminders on Android without the Google Calendar app?
I use the Google reminders a lot, and I find the integration with the Google Calendar app very useful. However, other than that, third-party calendar apps are generally better, in my view, than the Google one.
Is there a way to view (and edit) reminders with third party calendar apps?

Unless you mean something completely other than event reminders: Of course it is possible. The Google Calendar app is nothing but a front-end: you can even delete its data, and your events (including reminders) will still be there.
On your Android device, events are managed by a "background service" and are stored with an app called "calendar storage", which is part of the Android OS. Every calendar app can (and most do) interface with that.
So just give it a try – you will find it works fine!

I'm not talking about event reminders, but rather Google reminders (I don't know if that has a different name), such as Inbox reminders, or what Google Now generates when you say "remind me to buy milk tomorrow morning"

Oh. No idea about what Google Now/Assistant creates as I don't use that (though I always thought it were calendar events). But talking about Inbox reminders, that seems to be something different and not tied to the calendar subsystem – so in that case I'm not sure how it works and whether 3rd party calendar apps would pick it up. If you (try and) find out, please let us know (and ping me: though I don't use it nor ever will, I'd like to know).

Inbox reminders (and also keep and google now reminders) all appear in the calendar on the web and also in the official google calendar app, and they are indeed different.

And they don't appear in any 3rd party calendar app? Have you tried?

I tried in the default Samsung and Asus apps and in Outlook for Android.  None of them have that option.

Looks like those reminders are handled by the stock alarm clock, so you'd need a calendar app that also deals with stock alarms. Not that I've heard of any, but I never paid attention to that aspect so I might simply have missed it. So would "check your stock alarm clock" answer your question?

That link is ancient.  Reminders have changed a lot since them.  I wouldn't place much stock in them.

The page says 8/2016, so I didn't feel it that ancient. But now you write it, I took a closer look: no idea where they took that date from, all posts are indeed from 2013, apologies. No further ideas then.


text:
How to send an encrypted s/mime e‑mail?
Simple question, but I couldn’t find the answer anywhere…
I need to send encrypted e‑mails through using s/mime (talking about security, even most of metadata should be unknown). The problem is I’m not part of Google app organization (and I don’t need it since it’s not free).
How do I configure Gmail or the Samsung e-mail app to use the CA trusted certificate (which only contains public key) I installed on the device for sending enciphered e‑mails through s/mime ?
I also need to manually select the certificate which will be used for encryption (The company generate the paid certificate for me so it match my e-mail address and not company one).

You can't just configure an app to use S/MIME - it has to support it. Neither GMail nor the default Mail app support S/MIME AFAIK. Have you checked R2Mail2 and MailDroid?

@Robert yes I did. At that point, I wouldn’t mind about using the web interface, but I need to use my Gmail address for sending the messages. I heard the Google app for works supports encryption along acknowledgements but not with a Gmail address ending with gmail.com.

@Robert I also need to sign at the same time.

I am sorry I am giving up. Your question is still unclear. Have you set-up the Email client correctly to use use your S/MIME certificate - at least signing should be possible. If it not, you don't have to start trying to send encrypted mails.

@Robert no, simple I have a trusted cert matching my.email@gmail.com. But I have no public keys for department@company.com (but company.com has private key of certificate matching my.email@gmail.com). Most email client selects certificates automatically according to recipient, which mean they (softwares) try to find a public certificate for department@company.com, but since there’s no certificate verified for department@company.com, the e mail client refuses to encrypt the message and sending fails. What I need is to be able to manually select the certificate matching my.email@gmail.com.

@Robert It’s that simple ! Do you understand now ?

@Robert It’s that simple ! Is it clear ?

For the Samsung email app (on my Galaxy Tab A anyway) you need the following
▪An exchange activesync account - for some reason s/mime is not enabled for any other email type
▪Your public and private keys for your exchange account as a PKCS#12 cert uploaded to your tablet already or in your download directory ( root/sdcard/Download directory ) ready for import.
Go to the email settings > exchange account > security options screen and select the encryption certificate option then import. It should show you the PKCS#12 file and let you select it, enter any needed password and import it to your keystore with a friendly name of your choice. Repeat for the signing key - typicallly this is the same PKCS#12 file.
Set it to sign all outgoing mail if you wish - that'll help distribute your public key and maybe raises peoples awareness of s/mime.
It's probably not worth encrypting all outgoing messages by default as you'll get a warning for each recipient that you don't have their public key.
Send yourself test signed and then encrypted emails to prove this is working - preferably using a second device to test thoroughly. The three-dot menu on the send email will let you pick security options to sign and encrypt for individual messges.
The next stage is to try to exchange signed email with other real contacts - if you've defaulted to sign all this should just happen and they should be able to validate the signature.
The last stage is to send them an encrypted email, for that you need their public key / cert. If you've been exchanging signed email you should have it - hopefully you're also using exchange contacts and their record has their key else you'll need to add it from a received email.
Slightly concerning that you say the  recipient has a copy of your private key - this should never happen as your private key should always remain private to you. Officially you should revoke you key and get a new one. The practical upshot is things will get very confusing as to what's going on if you've got keys mixed up between public and private and sender and recipient. Good luck.
I don't think Samsung mail lets you easily swap your certs either - you can go into settings and change them but unless youre doing something interesting you should only have one email address on your exchange account.If you're trying to use encrypted group email I don't think Samsung email is going to help, and I don't know of any other mail client that can either.

I would definitely prefer using the offial ᴀᴘᴘ.

You need to use a mail app that supports, S/MIME. Check out Blackberry Hub app, K9 Mail, or others.
You can set up your gmail account as imap so that you send and receive using your gmail account.

Of course I already know that. The question is how ?

First you need an S/MIME certificate including private key for your selected E-Mail address.
If you don't have this you don't have to look for apps. AFAIK there is no "Let's Encrypt" for S/MIME therefore you have to buy the certificate for your e-mail address.
If you want to use your GMail account you have to enable IMAP on it.
Now you need an Android app that supports S/MIME signing and verifying. AFAIK the Google for enterprise apps are different form the regular apps, therefore the Gmail app won't work. As far as I know the following two apps should fully support S/MIME:

R2Mail2
MailDroid (not sure if S/MIME is supported in the free version)

The following apps won’t let me select a certificate manually. They complain that there is no certificates matching recipient. This is about using the same certificate for signing and encryption. If you found an app, also describe how to use encryption through the selecting the trusted certificate manually.

Do you have an S/MIME certificate including private key for your e-mail address (not for the recipient)? Because if not you can stop here. The rest only works if you have a valid S/MIME certificate for your account.

If you would have read my question correctly, you would have know that I have a trusted certificate for my e mail address. But I do not have a public certificate for recipient (recipient have a copy of my private key instead). so I can sign e mails but I cannot encrypt them.

So you have configured both GMail and the Samsung EMail client to use your S/MIME certificate? Note: S/MIME does not allow to send just an encrypted E-Mail to a recipient. Your own certificate also has to be installed (this prevents that you can't decrypt the mails stored in the sent folder).

Currently using Firefox extension. Yes, I installed my own (or rather third party provided and generated) certificate on system store. Again, that’s not fully certificate problem.


text:
Local IP address of Android device connected via Ethernet
I have an Android Tablet with Android 7.0 connected to my network via an OTG RJ45 Ethernet connector.
I know how to get local IP address when connected via WiFi, but not via Ethernet.
Any idea on how to do that (eventually with an app compatible with Nougat)?
Thanks

You can get the information you are looking for with the ifconfig command. On your android device install a terminal emulator app and open a local connection.

The ifconfig is a system administration utility in Unix-like operating systems for network interface configuration.

connect and setup your Ethernet connection.
Open the terminal app.
Enter the command ifconfig into the terminal.
scroll down and look for eth0 or close to that.
You should be able to find the ip address there.

Indeed. I was trying a terminal emulator but it was crashing. It worked nicely with Terminal Emulator for Android (https://play.google.com/store/apps/details?id=jackpal.androidterm). Thanks


text:
Creating a customized wallpaper
I have a small doubt about posting my question here. But still posting so that if wrong I might get the right site.

This is a wallpaper I found on the ZEDGE (click to enlarge)
This is a wallpaper I found on the ZEDGE app and I liked it. Now I just want to create my own customized wallpaper like this(to be precise, just replacing the words or some logos in this wallpaper), such as I wanted to put my own words etc.
Can anyone help me by telling me how that can be done on Android (basically).

If you want to modify that wallpaper, then you will need to find a photo editor and change whatever you want on it. For simply changing words on a picture, any photo editor will do, even one as simplistic as Microsoft Paint, as well as more complex options, like Photoshop and GIMP.
Although there are photo-editing apps available for Android, this isn't really an Android-specific question, since this process can be done on any platform, and therefore does not belong on this SE site. However, you probably needed an answer, and I chose to provide you one.
I hope this advice helps you do whatever you needed to do!


text:
How to Upgrade Sony Xperia Z3 Compact (D5803) to Android 8.1?
How do you upgrade the Sony Xperia Z3 Compact (D5803) to Android 8.1?
There are a number of web pages that attempt to answer this question, but none of them provide every step along the way. These include:

https://forum.xda-developers.com/z3-compact/general/z3-compact-marshmallow-to-oreo-step-step-t3720857
https://www.getdroidtips.com/omnirom-xperia-z3-compact-8-1-oreo/
https://rootmygalaxy.net/install-android-8-1-oreo-on-sony-xperia-z3-with-carbonrom-cr-6-1/
https://arnowelzel.de/en/carbonrom-on-the-sony-xperia-z3-compact
https://www.kbloghub.com/2018/02/root-install-twrp-recovery-on-sony-xperia-z3-compact.html
https://www.reddit.com/r/SonyXperia/comments/5vt6cs/flashing_marshmallow_concept_rom_on_a_sony_xperia/

They all skip steps or are missing key pieces of information that someone who is unfamiliar with the process would prevent from completing. A comprehensive, step-by-step guide for a complete novice would be helpful.

Disclaimer: unlocking the bootloader will lose some Sony proprietary DRM protected functionality, such as X-Reality Engine and Miracast. And there's no way to get it back if it's gone, unless you make a backup of a specific partition. More details here: https://www.xda-developers.com/restore-lost-functionality-unlocked-xperia/

Upgrade Sony Xperia Z3 Compact to Android 8.1
These instructions describe how to upgrade the Sony Xperia Z3 Compact (D5803) smart phone. These instructions do not include backup instructions, so be sure to save any important information and then proceed at your own risk.
Requirements

Laptop or Desktop - Windows 7
Xperia - Stock Build Number 23.5.A.1.291 (revert if necessary)
Xperia - Fully charged (100% recommended)
Xperia Companion
TWRP

Disclaimer
These instructions could brick your phone, rendering it a paperweight. Read all the instructions thoroughly at least once before you begin.
Unlocking the bootloader erases Sony's DRM-protected functionality, such as X-Reality Engine and Miracast. Unless you make a backup of a specific partition, the functionality will be permanently lost.
Enable Developer Mode
Enable developer mode on the phone as follows:

Power on the phone
Open Settings
Tap About phone
Scroll down to Build number
Tap Build number at least 7 times in succession
Enable developer mode

Developer mode is enabled.
Install Device Drivers
On the laptop or desktop computer, perform the following steps:

Disconnect Phone from USB, if not already disconnected
Download Flashtool v0.9.24.4 for Windows

Hint: Use BitPort.io and a throw away email service to download torrent (fast download)

Install into C:\Flashtool
Plug phone into laptop or desktop USB port
Run C:\Flashtool\drivers\Flashtool-drivers.exe
Check Flashboot Drivers
Scroll down
Check Xperia Z3 Compact Device Driver
Click Install
Accept any warnings that appear

The device drivers are installed.
Install Platform Tools
Download and install the Android Debug Bridge (ADB) as follows:

Download ADB platform tools
Unzip into C:\Program Files\platform-tools
Open a command prompt
Type: cd C:\Program Files\platform-tools
Type: adb devices
Authorize the connection on the phone.

The phone is listed and the ADB platform tools are installed.
Unblock the Bootloader
Advanced users can use Flashtool to unlock the bootloader, which is not described herein.
Unblock the phone's bootloader as follows:

Follow along with Sony's Guide
Complete Step 1: Check if the bootloader can be unlocked on your device
Skip Step 2: installing devices drivers and platform tools
Unplug the USB cable
Complete Step 3: Connect to Fastboot
Complete Step 4: Enter unlock key
Type: fastboot -i 0x0fce oem unlock 0x{UNLOCK CODE}

Replace {UNLOCK CODE} with the unlock code from Sony

The console shows:
...
OKAY [  1.544s]
finished. total time: 1.560s

The bootloader is unlocked.
Reboot
After the bootloader is unlocked, reboot the phone as follows:

Type: fastboot reboot
Wait for the reboot cycle to complete

The phone is rebooted with an unlocked bootloader.
TWRP
TWRP is a tool for writing custom software on mobile phones. Install TWRP as follows:

On the phone, visit https://twrp.me/sony/sonyxperiaz3compact.html
Install the Official TWRP App from the Play Store.
Download image into C:\Program Files\platform-tools:

twrp_z3c_O_2018-10-27.img

Power off phone
Unplug USB cable
Press and hold volume down
Plug in USB cable
Wait for blue indicator light in top left (may have to re-plug in)

Or run: adb reboot bootloader

Type: fastboot flash FOTAKernel twrp_z3c_O_2018-05-09.img

The output resembles:
target didn't report max-download-size
sending 'FOTAKernel' (10730 KB)...
OKAY [  0.345s]
writing 'FOTAKernel'...
OKAY [  0.722s]
finished. total time: 1.075s

TWRP recovery mode application is installed, to assist flashing ROM.
ROM
A handful of ROMs exist. When choosing a ROM, also find the version of GApps that is suitable for the selected ROM. The Sony Xperia Z3 Compact uses a Snapdragon 801 Processor, which has a 32-bit architecture.
Note: These instructions have only been successfully accomplished using CarbonROM and MindTheGapps.
CarbonROM 6.1
Download CarbonROM from:

https://mirrorbits.carbonrom.org/z3c/CARBON-CR-6.1-NOCT-RELEASE-z3c-20200323-0711.zip

Download the ARM architecture version of MindTheGapps from:

http://downloads.codefi.re/jdcteam/javelinanddart/gapps

Alternatively, download the 32-bit ARM architecture version of Open GApps for Android version 8.1 from:

https://opengapps.org/?api=8.1&variant=nano

The version of Open GApps must match the Android version of CarbonROM.
Skip to the General ROM Installation section.
LineageOS 15.1
Download LineageOS from (forum post):

https://rapidgator.net/file/1f8a3bdde3cd7ef6a19e9d87c314007b/lineage-15.1-20171103-UNOFFICIAL.zip.html

Skip to the General ROM Installation section.
OmniROM Oreo 8.1
Download OmniROM Oreo from either of the following sites (forum post):

https://releases.nailyk.fr/omni/z3c/omni-8.1.0-20180320-z3c-nailyk.zip
https://drive.google.com/open?id=15COhmKqMBMiVeSLONSs38DaKymH2TWsv

Continue to the General ROM Installation section.
General ROM Installation
The ROM filename will differ, depending on the ROM that was downloaded, such as:

CarbonROM: CARBON-CR-6.1-NOCT-WEEKLY-z3c-20180605-0603.zip
OmniROM: omni-8.1.0-20180320-z3c-nailyk.zip
LineageOS: lineage-15.1-20171103-UNOFFICIAL.zip

The steps to flash a given ROM are as follows:

Reboot the phone using: fastboot reboot
Start Xperia Companion
Click Browse Xperia
Copy both the ROM and the Gapps files into the phones download directory (e.g., Computer\Xperia Z3 Compact\Internal storage\Download\)

Power off phone
Unplug phone
Press and hold the volume down button
Press and hold the power button
Wait for a slight vibration before releasing both buttons
Wait for recovery application to load
Swipe to allow modifications
Select WIPE
Select Advanced
Check the following:

Dalvik / ART cache
System
Cache
Data

Swipe to confirm wipe
Tap Home icon
Tap Install
Browse to and select the OS ROM file
Tap Add more Zips
Browse to and select the GApps file
Swipe to confirm Flash
Tap Reboot System
Wait for the boot to complete

Android and the GApps are installed using the specified ROM.

A small note to Dave Jarvis' answer:
I almost gave up, just getting adb/fastboot talking to the device.
Turned out to be a Windows 10 problem, because it refused without notice (?) to install drivers. The flashtool64 did complain however that it failed 2  of 3 in one of its windows, but I assumed (wrongly) that it was okay. I followed this guide to disable driver signature enforcement:

Please check if you have performed these steps to disable the driver signature enforcement in Windows 10 Technical Preview.

Press the Win + C and click on PC settings.
Switch over to the “Update & recovery” section.
Then click on the Recovery option on the left hand side.
Once selected, you will see an advanced startup section appear on the right hand side. You will need to click on the “Restart now” button.
Once your Computer has rebooted you will need to choose the Troubleshoot option.
Then head into Advanced options.
Then Startup Settings.
Since we are modifying boot time configuration settings, restart your computer once more.
Here you will be given a list of startup settings that you can change. The one we are looking for is “Disable driver signature enforcement”. To choose the setting, you will need to press F7.

Once this was done, the drivers were installed from guide links and with flashtool64, and then I got a message that the adb "was too old", so they were updated as well.
Note: If you follow the guide, you will have new adb drivers. I assumed wrong (again) that my present ones would suffice.


text:
How to enable mac address filtering in Wi-Fi Access Point on android 8.1?
I can do this by modifying /data/misc/wifi/hostapd.conf directly on android 6.0.1,but android 8.1 always covers it.
Namely,can I run hostapd manually without settiings?I tried this,but looks like  the wifi device is disable:
#hostapd -e /data/misc/wifi/entropy.bin /data/misc/wifi/hostapd.conf exited with code 1,and logcat shows "Could not read interface wlan0 flags: No such device".
How should I enable it?
Wifi is enable in settings:
#ip link show
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: bond0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default
    link/ether **:8d:**:5b:**:fa brd ff:ff:ff:ff:ff:ff
3: dummy0:  mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default
    link/ether **:c8:**:b0:**:c6 brd ff:ff:ff:ff:ff:ff
4: sit0@NONE:  mtu 1480 qdisc noop state DOWN mode DEFAULT group default
    link/sit 0.0.0.0 brd 0.0.0.0
5: rmnet_ipa0:  mtu 2000 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 1000
    link/[530]
6: rmnet_data0:  mtu 1500 qdisc htb state UNKNOWN mode DEFAULT group default qlen 1000
    link/[530]
7: rmnet_data1:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/[530]
and more rmnet_data...
34: wlan0:  mtu 1500 qdisc mq state UP mode DORMANT group default qlen 3000
    link/ether **:03:**:c2:**:43 brd ff:ff:ff:ff:ff:ff
35: p2p0:  mtu 1500 qdisc mq state DOWN mode DORMANT group default qlen 3000
    link/ether **:03:**:c2:**:43 brd ff:ff:ff:ff:ff:ff

$ls /sys/devices/soc/600000.qcom,pcie/pci0000:00/0000:00:00.0/0000:01:00.0
broken_parity_status
class
config
consistent_dma_mask_bits
device
devspec
dma_mask_bits
driver
driver_override
enable
ieee80211
iommu_group
irq
local_cpulist
local_cpus
modalias
msi_bus
net
power
remove
rescan
reset
resource
subsystem
subsystem_device
subsystem_vendor
uevent
vendor
Wifi is disable in settings:
#ip link show
1: lo:  mtu 65536 qdisc noqueue
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: bond0:  mtu 1500 qdisc noop
    link/ether **:8d:**:5b:**:fa brd ff:ff:ff:ff:ff:ff
3: dummy0:  mtu 1500 qdisc noqueue
    link/ether **:c8:**:b0:**:c6 brd ff:ff:ff:ff:ff:ff
4: sit0@NONE:  mtu 1480 qdisc noop
    link/sit 0.0.0.0 brd 0.0.0.0
5: rmnet_ipa0:  mtu 2000 qdisc pfifo_fast qlen 1000
    link/[530]
6: rmnet_data0:  mtu 1500 qdisc htb qlen 1000
    link/[530]
7: rmnet_data1:  mtu 1500 qdisc noop qlen 1000
    link/[530]
and more rmnet_data...
wlan0 is missed.
$ls /sys/devices/soc/600000.qcom,pcie/pci0000:00/0000:00:00.0/0000:01:00.0
broken_parity_status
class
config
consistent_dma_mask_bits
device
devspec
dma_mask_bits
driver
driver_override
enable
iommu_group
irq
local_cpulist
local_cpus
modalias
msi_bus
power
remove
rescan
reset
resource
subsystem
subsystem_device
subsystem_vendor
uevent
vendor
net and ieee80211 are missed.

"can I run hostapd manually without settiings?" Do you mean like through an adb shell? I believe so if you are rooted. This command might start it adb shell su -c hostapd -B /data/misc/wifi/hostapd.conf

@BoLawson I tried,#hostapd -e /data/misc/wifi/entropy.bin /data/misc/wifi/hostapd.confexited with code 1,and logcat shows "Could not read interface wlan0 flags: No such device".I've edited the question.


text:
How to make network calls on Android with an app in the background
I am building a react-native app that launches a series of network requests (both UDP, HTTP) when it receives a special kind of notification, or based on a delayed execution.
However it turns out that after the first or second call, it enqueues the calls, without making them. If I open the applications, the remaining network calls are made, and the process continues.
It's a normal issue given that there is a specific doc page inside Android documentation targeting this behaviour:

Excessive Wi-Fi Scanning in the Background
Background Execution Limits

I have read and research over SO: https://stackoverflow.com/questions/40216992/best-place-to-make-network-calls, https://stackoverflow.com/questions/49048434/how-to-make-network-call-from-background-service but those methods did not work to bypass the obstacle. I can require the user to deactivate "battery optimisation" if required, but that did not work either.
I should mention that I am using React Native in order to handle the lifecycle and trigger the network calls, so they are running inside an Activity that is not in the background or when the phone is locked. I believe there should be ways moving things to a) a background thread or b) an Android service.
I really appreciate any response, experience or links that would help me address this problem.


text:
How do I simulate menu button on Android 8?
So far I've used the Assistant Menu on my Galaxy S7 as recommended in this question, but after a recent update the assistant menu no longer contains the old menu button.
The "long press" suggestions in the answers doesn't work for me either.

Same problem here.  Found an app called "Menu Button" in the play store which has solved my issue with an old app (Loot personal finance).  I have no association with this app.


text:
How to hide navigation bar on home screen of Samsung J6
How to hide the navigation bar on home screen of Samsung J6?

Maybe that in the Settings app, you could setup the full screen mode setting especially for the default samsung launcher.
By this way you could hide the navigation bar, or the statubar or the navigation bar and the statubar.