Android activity中单击返回键或home键彻底退出应用

@Override

    public boolean onKeyDown(int keyCode, KeyEvent event) {

        if(keyCode == KeyEvent.KEYCODE_BACK||keyCode == KeyEvent.KEYCODE_HOME){

            finish();

        }

        return super.onKeyDown(keyCode, event);

    }

    @Override

    protected void onDestroy() {

        System.exit(0);

        super.onDestroy();

    }