[android] "android.view.WindowManager$BadTokenException: Unable to add window" on buider.show()

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.

: )