Android 實現再按一次後退鍵退出應用程序

Android 實現再按一次後退鍵退出應用程序

private boolean isexit = false;
private boolean hastask = false;
Timer texit = new Timer();

TimerTask task = new TimerTask() {
        public void run() {
        isexit = false;
        hastask = true;
        }
    };

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){
            //DialogAPI.showExit(this);
            if(isexit == false){
                isexit = true;
                Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show();
                if(!hastask) {
                    texit.schedule(task, 2000);
                }
            }else{
                finish();
                System.exit(0);
            }
            return false;
            }

        return super.onKeyDown(keyCode, event);
    }