Android Activity capture return button to close application method

Android Activity capture return button to close application method

@Override public boolean onKeyDown (int keycode, keyevent event) {  //press the Back button on the keyboard  if (keycode = = Keyevent.keycode_ Back) {      new Alertdialog.builder (this).   SetIcon (R.drawable.alert_dialog_icon).   settitle ("hint")   . Setmessage ("Do you want to close the app?")   . Setnegativebutton ("Cancel", new Dialoginterface.onclicklistener () {public    void OnClick (dialoginterface dialog, int which) {    }   })   . Setpositivebutton ("OK", new Dialoginterface.onclicklistener () {public    void OnClick (dialoginterface dialog, int whichbutton) {     zhuzhuapp.exit ();    }   }). Show ();        return true;  } else{     return Super.onkeydown (KeyCode, event);}  }