系统秒数
···
//加上返回监听对话框
public class MainActivity extends AppCompatActivity{
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode==KeyEvent.KEYCODE_BACK){//判断是返回键
exit();
return false;
}
return super.onKeyDown(keyCode,event);
}
private long exitTime=0;//用来保存上一次的时间
private void exit() {
if ((System.currentTimeMillis()-exitTime)>2000){//判断上次按的秒速
Toast.makeText(getApplicationContext(),"再按一次退出",Toast.LENGTH_SHORT).show();
Log.e("tag","System.currentTimeMillis()"+System.currentTimeMillis());
exitTime=System.currentTimeMillis();
}else{
finish();//关闭页面
System.exit(0);
}
}
}
···
使用Handler
image.png
