[代码]捕获返回键，弹出是否确定返回应用MainMenu的对话框

捕获返回键，弹出是否确定返回应用MainMenu的对话框

public boolean onKeyDown(int keyCode, KeyEvent event) {                
   if(keyCode == KeyEvent.KEYCODE_BACK){
      new AlertDialog.Builder(this)
       .setIcon(R.drawable.icon)
       .setTitle(R.string.app_name)
       .setMessage(R.string.quit_desc)
       .setNegativeButton(R.string.quit_cancel, new DialogInterface.OnClickListener() {
          @Override
          public void onClick(DialogInterface dialog, int which) {
                                }
              })
       .setPositiveButton(R.string.quit_confirm, new DialogInterface.OnClickListener() {
          public void onClick(DialogInterface dialog, int whichButton) {
               Intent myIntent;
               myIntent = new Intent(PictureScribble.this, MainMenu.class);
               startActivity(myIntent);
               PictureScribble.this.finish();
                  }
               }).show();
               return true;
    }else{                
          return super.onKeyDown(keyCode, event);
    }
}