“android.view.WindowManager$BadTokenException: Una

Question

From my main activity, I need to call an inner class and in a method within the class, I need to show AlertDialog. After dismissing it, when the OK button is pressed, forward to Google Play for purchase.

Things work perfectly for most of the times, but for few users it is crashing on builder.show() and I can see "android.view.WindowManager$BadTokenException: Unable to add window" from crash log. Please suggest.

My code is pretty much like this:

public class classname1 extends Activity{

  public void onCreate(Bundle savedInstanceState) {
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.<view>); 

    //call the <className1> class to execute
  }

  private class classNamename2 extends AsyncTask<String, Void, String>{

    protected String doInBackground(String... params) {}

    protected void onPostExecute(String result){
      if(page.contains("error")) 
      {
        AlertDialog.Builder builder = new AlertDialog.Builder(classname1.this);
        builder.setCancelable(true);
        builder.setMessage("");
        builder.setInverseBackgroundForced(true);
        builder.setNeutralButton("Ok",new DialogInterface.OnClickListener() {
          public void onClick(DialogInterface dialog, int whichButton){
            dialog.dismiss();
            if(!<condition>)
            {
              try
              {
                String pl = ""; 

                mHelper.<flow>(<class>.this, SKU, RC_REQUEST, 
                  <listener>, pl);
              }

              catch(Exception e)
              {
                e.printStackTrace();
              }
            }  
          }
        });

        builder.show();
      }
    }
  }
}

I have also seen the error in another alert where I am not forwarding to any other activity. It's simple like this:

AlertDialog.Builder builder = new AlertDialog.Builder(classname1.this);
    builder.setCancelable(true);

    //if successful
    builder.setMessage(" ");
    builder.setInverseBackgroundForced(true);
    builder.setNeutralButton("Ok",new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int whichButton){
            // dialog.dismiss();
                   }
    });
    builder.show();
}

Answer 1

with this globals variables idea, I saved MainActivity instance in onCreate(); Android global variable

public class ApplicationController extends Application {

    public static MainActivity this_MainActivity;
}

and Open dialog like this. it worked.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Global Var
    globals = (ApplicationController) this.getApplication();
    globals.this_MainActivity = this;
}

and in a thread, I open dialog like this.

AlertDialog.Builder alert = new AlertDialog.Builder(globals.this_MainActivity);

1. Open MainActivity
2. Start a thread.
3. Open dialog from thread -> work.
4. Click "Back button" ( onCreate will be called and remove first MainActivity)
5. New MainActivity will start. ( and save it's instance to globals )
6. Open dialog from first thread --> it will open and work.

: )