Android project suddenly ruined, cant find R object
<p>R cannot be resolved to a variable
so i tried to do "fix project setup", but then it cant identify all of its subcontent, such as objects from my xml, R.id.X, R.drawable.Y, none of them are identified.
I just tried to follow <a href="http://developer.android.com/guide/topics/ui/controls/pickers.html" rel="nofollow">http://developer.android.com/guide/topics/ui/controls/pickers.html</a> guide and add such class to have a dialog for choosing time.</p>

<pre><code>    Description Resource    Path    Location    Type
users cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 170    Java Problem
ic_launcher cannot be resolved or is not a field    MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 159    Java Problem
about cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 136    Java Problem
menu_user cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 133    Java Problem
imp_logo cannot be resolved or is not a field   MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 198    Java Problem
activity_main cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 44 Java Problem
timerCB cannot be resolved or is not a field    MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 64 Java Problem
timerTime cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 65 Java Problem
statusText cannot be resolved or is not a field MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 66 Java Problem
timerText cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 67 Java Problem
start_button cannot be resolved or is not a field   MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 68 Java Problem
stop_button cannot be resolved or is not a field    MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 69 Java Problem
activity_main cannot be resolved or is not a field  MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 123    Java Problem
menu_url cannot be resolved or is not a field   MainActivity.java   /RemoteSwitch/src/com/example/remoteswitch  line 130    Java Problem
</code></pre>
