Android上需要倒数计时器

public class MainActivity extends AppCompatActivity {

    private TextView countdownText;
    private CountDownTimer countDownTimer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        countdownText = findViewById(R.id.countdown_text);

        // 设置倒计时总时长为60秒，每次倒计时间隔为1秒
        countDownTimer = new CountDownTimer(60000, 1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                // 每次倒计时间隔执行的操作
                countdownText.setText("倒计时：" + millisUntilFinished / 1000 + "秒");
            }

            @Override
            public void onFinish() {
                // 倒计时结束执行的操作
                countdownText.setText("倒计时结束");
            }
        };

        // 开始倒计时
        countDownTimer.start();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 取消倒计时
        countDownTimer.cancel();
    }
}