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POAction bar home button crashes while back button works
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copied!<p>I'm completely stumped on this one. I have an activity C, when I try and press the back button, it works. But when I use the home/up button in the action bar it just crashes with (see the following error). Here are the parts of my code which deal with the back/up buttons.</p> <p>Activity C:</p> <pre><code>protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_offline_viewer); ActionBar actionBar = getActionBar(); actionBar.setDisplayHomeAsUpEnabled(true); } @Override public boolean onPrepareOptionsMenu(Menu menu) { if(!isOnline) { menu.removeItem(R.id.saveRoute); } return true; } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.offline_viewer, menu); return true; } @Override public void onBackPressed() { super.onBackPressed(); finish(); } @Override public boolean onOptionsItemSelected(MenuItem item) { //Get names for saving String[] startParts = onlineFrom.split(","); String startName = startParts[0] + "," + startParts[1]; String[] endParts = onlineTo.split(","); String endName = endParts[0] + "," + endParts[1]; System.out.println(item.getItemId()); switch(item.getItemId()){ //Save xml file or route once pressed case R.id.saveRoute: //TODO:Uncomment once server is ready new DownloadFileFromURL(this, startName, endName).execute(urlForDownload); return true; case android.R.id.home: System.out.println(item.getItemId()); onBackPressed(); return true; } return super.onOptionsItemSelected(item); } </code></pre> <p>Error:</p> <pre><code>08-22 16:15:43.629: W/dalvikvm(4908): threadid=1: thread exiting with uncaught exception (group=0x41c7e888) 08-22 16:15:43.634: E/AndroidRuntime(4908): FATAL EXCEPTION: main 08-22 16:15:43.634: E/AndroidRuntime(4908): java.lang.NullPointerException 08-22 16:15:43.634: E/AndroidRuntime(4908): at com.example.otpxmlgetter.OfflineViewer.onOptionsItemSelected(OfflineViewer.java:185) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.app.Activity.onMenuItemSelected(Activity.java:2590) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:361) 08-22 16:15:43.634: E/AndroidRuntime(4908): at com.android.internal.widget.ActionBarView$3.onClick(ActionBarView.java:167) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.view.View.performClick(View.java:4204) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.view.View$PerformClick.run(View.java:17354) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.os.Handler.handleCallback(Handler.java:725) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.os.Handler.dispatchMessage(Handler.java:92) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.os.Looper.loop(Looper.java:137) 08-22 16:15:43.634: E/AndroidRuntime(4908): at android.app.ActivityThread.main(ActivityThread.java:5232) 08-22 16:15:43.634: E/AndroidRuntime(4908): at java.lang.reflect.Method.invokeNative(Native Method) 08-22 16:15:43.634: E/AndroidRuntime(4908): at java.lang.reflect.Method.invoke(Method.java:511) 08-22 16:15:43.634: E/AndroidRuntime(4908): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794) 08-22 16:15:43.634: E/AndroidRuntime(4908): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:561) 08-22 16:15:43.634: E/AndroidRuntime(4908): at dalvik.system.NativeStart.main(Native Method) </code></pre> <p>Does this have something to do with the fact that there are two possible ways to get to Activity C? Either A->B->C or A->D->C? The fact that the back button still works completely confounds me.</p>

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