Android中再按一下返回键退出程序

 

private static Boolean isExit = false;

private static Boolean hasTask = false;

Timer tExit = new Timer();

TimerTask task = new TimerTask() {

@Override

public void run() {

isExit = ture;

hasTask = true;

}

};

@Override

public boolean onKeyDown(int keyCode, KeyEvent event) {

System.out.println("TabHost_Index.java onKeyDown");

if (keyCode == KeyEvent.KEYCODE_BACK) {

if(isExit == false ) {

isExit = true;

Toast.makeText(this, "再按一次后退键退出应用程序", Toast.LENGTH_SHORT).show();

if(!hasTask) {

tExit.schedule(task, 2000);

}

} else {

finish();

System.exit(0);

}

}

return false;

}