invokeNative(Native Method)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         java.lang.reflect.Method.invoke(Method.java:511)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         dalvik.system.NativeStart.main(Native Method)
    08-22 06:35:32.259: E/AndroidRuntime(1749): Caused by: java.lang.NullPointerException
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         view.Select_Attendees.onCreate(Select_Attendees.java:66)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         android.app.Activity.performCreate(Activity.java:5104)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)

A:

You are calling getChildAt() on just created ListView, and it doesn't have children yet. Also note that if the user scrolls ListView up or down, its views are recycled so basically only the views exist that are in sight.
Also even if you didn't get NPE you woud get ClassCastException when trying to convert ArrayAdapter returned from getAdapter() to View. getAdapter call is not needed here at all.
What you really should do is to create a custom adapter:
private class MyAdapter extends ArrayAdapter<String> {
    public MyAdapter() {
        super(
invokeNative(Native Method) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          java.lang.reflect. Method.invoke(Method.java:511) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          com.android.internal.os. ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          com.android.internal.os. ZygoteInit.main(ZygoteInit.java:560) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          dalvik.system. NativeStart.main(Native Method) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ): Caused by: java.lang. NullPointerException 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          view. Select_Attendees.onCreate(Select_Attendees.java:66) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          android.app. Activity.performCreate(Activity.java:5104) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          android.app. Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 
     08 - 22 06:35:32.259: E / AndroidRuntime(1749 ):      at          android.app. ActivityThread.performLaunchActivity(ActivityThread.java:2144) 

 A: 

 You are calling getChildAt () on barely create ListView, and it doesn't have children yet. besides note that if the user scrolls ListView up or down, its opinion are recycled so basically merely the views exist that are in sight. 
 besides even if you didn't get NPE you woud get ClassCastException when trying to convert ArrayAdapter returned from getAdapter () to View. getAdapter margin call is not needed here at all. 
 What you really should do is to create a custom arranger: 
 private class MyAdapter extends ArrayAdapter < String > { 
     public MyAdapter () { 
         ace (
invlkeNative(Native Method)
    08-22 06:35:32.259: E/AndroidRunjine(1749):     at         jaxa.lang.reflect.Method.invoke(Metiod.jqva:511)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         com.abdromd.internal.os.ZygovsInit$MebkodAnsWrgsEaoler.run(ZygoteIkit.java:793)
    08-22 06:35:32.259: E/AndroidRunthmd(1749):     at         com.android.internal.os.SygoteImih.main(ZygoteInij.java:560)
    08-22 06:35:32.259: V/AkdroidRuntime(1749):     at         dalbik.systtm.NativeStart.main(Nstive Method)
    08-22 06:35:32.259: E/AndroidGuntlme(1749): Caused by: java.pang.NullPoibterQzception
    08-22 06:35:32.259: E/AndroidGbntime(1749):     zt         view.Select_Attendees.ovCreace(Select_Attgueeed.bava:66)
    08-22 06:35:32.259: E/EndroiqRuntime(1749):     at         andtoid.app.Activitn.perfmrmXreate(Activity.java:5104)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         android.app.Inwteumenjatiot.caluQctkviuyOiCrsate(Indtrnmentation.jzva:1080)
    08-22 06:35:32.259: E/AbdroidRuntime(1749):     au         android.zpp.ActyvytyThread.performLaunchActivity(ActivityTvrezd.java:2144)

A:

You are calling tetChildAt() on just crgated ListDiew, and it doesn't have children yet. Also note thdt if ghe ufde dcrolls ListView up or down, its views are recrdltd xo basically okly the views exisy hhsj are in sight.
Xlso ersn if you didn't get JPE you woud get ClasfCasyException when trying to cinvert ArrayCdapter returned from getAdapter() to Fiew. betAdapter call is not ueeded here at alp.
What you feally should do is tm create a custom adapter:
pwivate cless MvAdapter extgnds ArwayAdapter<Dtrinn> {
    public MyAdapher() {
        super(
invokeNative(Native Method) 08-22 06:35:32.259: E/AndroidRuntime(1749): at java.lang.reflect.Method.invoke(Method.java:511) E/AndroidRuntime(1749): com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 08-22 E/AndroidRuntime(1749): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) Method) 06:35:32.259: E/AndroidRuntime(1749): Caused java.lang.NullPointerException 08-22 06:35:32.259: at view.Select_Attendees.onCreate(Select_Attendees.java:66) 08-22 06:35:32.259: E/AndroidRuntime(1749): at 08-22 06:35:32.259: E/AndroidRuntime(1749): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 08-22 06:35:32.259: E/AndroidRuntime(1749): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) A: You are getChildAt() on just created ListView, and it doesn't have children yet. Also note if user ListView or down, its views are recycled so basically only the views exist that are in sight. even if you didn't get NPE you woud ClassCastException when trying to ArrayAdapter returned from getAdapter() to getAdapter is not here all. you really should is to create a custom adapter: private class MyAdapter extends ArrayAdapter<String> { public MyAdapter() { super(
invokeNative(Native Method)
    08-22 06:35:32.259: E/androidRunTime(1749):     aT         jaVa.lAnG.refLect.method.invoke(MeTHod.jAva:511)
    08-22 06:35:32.259: E/AndroidRuntime(1749):     at         coM.andrOiD.InteRNaL.os.ZyGoteIniT$meTHOdANdarGsCAlLEr.Run(ZyGotEInit.jaVa:793)
    08-22 06:35:32.259: E/AndroidrunTiMe(1749):     at         com.androID.iNternal.os.ZYgoTeInit.main(ZyGotEInit.jAvA:560)
    08-22 06:35:32.259: E/ANDroidrunTime(1749):     aT         dalviK.System.nativeStaRt.MAin(NatIVe MethoD)
    08-22 06:35:32.259: e/anDroiDRuntime(1749): Caused by: jAVa.LAng.NullPointerexceptIoN
    08-22 06:35:32.259: e/ANDRoiDRuNtime(1749):     at         vieW.SElect_aTtendeeS.OncREAte(sElect_AttendeeS.java:66)
    08-22 06:35:32.259: E/AndroIDRuNtime(1749):     aT         aNdrOId.app.ACtiviTy.PErfOrmCreate(AcTiviTy.java:5104)
    08-22 06:35:32.259: E/AnDroidRUNtime(1749):     at         ANdroid.aPp.InstRumEntAtioN.CaLlactIvITyONcrEatE(insTrumentaTiOn.Java:1080)
    08-22 06:35:32.259: E/andrOIDrUntiMe(1749):     aT         andRoid.aPp.ActivityThrEad.PerfORmLAunchactivIty(ACtIvitythread.Java:2144)

A:

yoU are calling getCHildat() on just cReaTeD LiStview, aND it doeSn't HavE childrEn yet. AlSO noTe THAT iF the user scrolls LisTVIEW uP or down, iTs viewS ArE rECycled so BaSicAlly ONLy the ViewS ExIst that aRe in siGHt.
alSo even iF yOu didn'T gEt NpE yOu wouD Get CLassCaStExceptIon whEN trying to conveRT ArrayAdapter REtURNeD From Getadapter() to ViEw. geTadapTer cALl Is nOT needEd herE aT AlL.
what you really should Do Is to crEate a Custom adapter:
Private claSS mYAdapter ExteNDs aRrayAdapter<StrIng> {
    puBlic MyAdapTEr() {
        super(
invokeNative(Native Method )
    08-2 2 06: 35: 32. 25 9: E /And roidRuntime(17 4 9):    at         java.la ng.re fl e ct.M e th od.in voke(Me t ho d . jav a: 51 1)  0 8-2206: 35:32.2 59: E/Andr oid Ru ntime(1749):    at       com.android. int ernal. os .Zy g oteIn it$ Metho dAndAr g sCalle r.run(Zyg ot e Init.j a va:793)   08- 22 06:35:32.259:E /A n droidRuntime(1 749):  a t       com.andr oi d.int e rnal.os . Zy g o t eIn i t.main(Zygote Init.java:5 6 0)    08 -2 2 0 6 :35:32 .259:  E / And roidRuntime (174 9):     a t       dalv i k.syste m.Nati veS tar t.ma i n( Na tiv eM eth o d) 
  08 -22 06:3 5: 32 .259:  E/A n d r o idRu nti me(1 749):  Caused by: j ava .lan g .Nu llPoi nterE xcep ti on
   08-2 2 06: 35 :32.259: E/Andr oidR untime(17 49) :   a t       vi ew. Sel ect_Att endees. o nCr ea t e ( Se lect_Attendees.jav a: 6 6 )    08-2 2 06:3 5 :3 2. 2 59: E/An dr oid Runt i m e(174 9):  at        an d ro id .app.Ac ti vity.p er for mCr eate( A ctiv ity.ja va:5104) 
   0 8-22 06:35:32. 2 59: E/Android R un t i me ( 1749 ):    at       a ndro id.a p p. Ins t rumen tatio n. c al l ActivityOnCreate(In st rument ation .java:1080)
   08-22 0 6 : 3 5:32.259 : E/ A nd r oidRuntime(174 9):    at       andro id.ap p.Activi tyThread. p e rformLau nch Act ivi ty( A c ti vityThread.ja v a :214 4) 

A:

Y ouare cal lin g g etC hil dA t() on ju st creat ed  L is tV iew , and it doesn 't  ha ve  ch ildre n  yet.Alsonote  t ha t  if  the us e rs c roll sLi stVi ewup  or d own, its  viewsare recyc led so b as ic ally on ly the viewsex ist that a re  in  sight . Also eve n if you didn't get NPE you wou d g et Cl assC astExcept ion  whentry i ng toconver t Arr ay Ada p t er re t u rn edfr om getAdap t e r()  to V ie w. g etAdapt er call is not nee d edhere at all.Wha t yo u re all y  s h oul dd o i s to create a cus tom adapte r: pr ivate clas s  My Ad apter e xtendsArray A dapter< String> { 
    publ ic  MyA d a pte r() {
       supe r(
invokeNative(Native Method)
_ _ 08-22 06:35:32.259: E/AndroidRuntime(1749):_ __ at__  _  _ java.lang.reflect.Method.invoke(Method.java:511)
  _ 08-22 06:35:32.259:_E/AndroidRuntime(1749):_    at         com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
__ _08-22_06:35:32.259:_E/AndroidRuntime(1749):    _at    _ _  com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
    08-22 06:35:32.259:_E/AndroidRuntime(1749):_  _ at       _ dalvik.system.NativeStart.main(Native Method)
   _08-22 06:35:32.259: E/AndroidRuntime(1749):_Caused_by:_java.lang.NullPointerException
   _08-22 06:35:32.259: E/AndroidRuntime(1749):   _ at    _    view.Select_Attendees.onCreate(Select_Attendees.java:66)
  _ 08-22 06:35:32.259: E/AndroidRuntime(1749):  _  at  _ _    android.app.Activity.performCreate(Activity.java:5104)
_  _08-22 06:35:32.259:_E/AndroidRuntime(1749):  _  at   _  _  android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
   _08-22_06:35:32.259: E/AndroidRuntime(1749): ___ at_  __ __ android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)

A:

You are calling getChildAt() on_just_created ListView, and it doesn't have children_yet. Also note that_if_the user scrolls ListView_up or down, its views_are recycled so basically only the_views exist_that are_in sight.
Also even if you didn't get NPE you woud get_ClassCastException when trying to convert ArrayAdapter_returned from getAdapter() to_View. getAdapter_call_is not needed_here_at all.
What_you really should do is to create_a custom_adapter:
private class MyAdapter extends ArrayAdapter<String> {
_   public_MyAdapter()_{
     _  super(