progress dialogue box giving exception in asynchtask [duplicate]

Question

I am developing an android application in which i m using an asynchronous task an in post execute method when i m closing progress dialogue box an exception is coming and application is closing forcefully.

Exception coming is:

    04-24 09:41:54.661: E/AndroidRuntime(1727): java.lang.IllegalArgumentException: View not attached to window manager
    04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.view.WindowManagerImpl.findViewLocked(WindowManagerImpl.java:355)

The code:

data_insertion = new AsyncTask<Void, Void, Void>() {
  @Override
  protected void onPreExecute() {
    // TODO Auto-generated method stub             
    CommonUtility.show_PDialog(MainActivity.this);
    super.onPreExecute();
  }
  @Override
  protected void onPostExecute(Void result) {
    // TODO Auto-generated method stub
    //setting alaram for refresh api 
    CommonUtility.close_PDialog(); //*getting exception on this line* 
    Intent setalaram = new Intent(MainActivity.this, SetAlaram.class);
    startService(setalaram);
    Intent i = new Intent(MainActivity.this, PlayListActivity.class);
    startActivity(i);
    MainActivity.this.finish();
    super.onPostExecute(result);
    finish();
  }
  @Override
  protected Void doInBackground(Void...params) {
    // TODO Auto-generated method stub
    //some code 
  }
  return null;
}
}.execute(null, null, null); 

//and here is my close method for dilogue
public static void close_PDialog() {
  if (dialog != null && dialog.isShowing()) {
    dialog.dismiss();
  }
}

log output:

04-24 09:41:54.661: E/AndroidRuntime(1727): FATAL EXCEPTION: main
04-24 09:41:54.661: E/AndroidRuntime(1727): java.lang.IllegalArgumentException: View not attached to window manager
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.view.WindowManagerImpl.findViewLocked(WindowManagerImpl.java:355)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.view.WindowManagerImpl.removeView(WindowManagerImpl.java:200)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.view.Window$LocalWindowManager.removeView(Window.java:432)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.app.Dialog.dismissDialog(Dialog.java:278)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.app.Dialog.access$000(Dialog.java:71)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.app.Dialog$1.run(Dialog.java:111)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.app.Dialog.dismiss(Dialog.java:268)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at commonUtilities.CommonUtility.close_PDialog(CommonUtility.java:233)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at com.walkover.filesharing.MainActivity$1.onPostExecute(MainActivity.java:55)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at com.walkover.filesharing.MainActivity$1.onPostExecute(MainActivity.java:1)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.os.AsyncTask.finish(AsyncTask.java:417)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.os.AsyncTask.access$300(AsyncTask.java:127)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.os.Looper.loop(Looper.java:130)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at android.app.ActivityThread.main(ActivityThread.java:3683)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at java.lang.reflect.Method.invokeNative(Native Method)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at java.lang.reflect.Method.invoke(Method.java:507)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-24 09:41:54.661: E/AndroidRuntime(1727):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

Possibly when the task ends, and runs on its onPostExecute, the Activity it was created in (and it got the context from) was already destroyed when it came to the onPostExecute.

You could leave it this way, or make one progressDialog instance somewhere that can be used every time you need a dialog, and in the onDestroy() method of your activity you could cancel it (in case something like this happens).