// the count down timer


 new  CountDownTimer(30000, 1000)
         {
        @Override
        public void onTick(long l) {

        }
        @Override
        public void onFinish() {
        
                //on finish the count down timer finsih        
                         }
          
            }
        }

    }.start();

如CountDownTimer的文档所示:

new CountDownTimer(30000, 1000) { onTick(long milliseconds untilfinished) { mTextField。setText("seconds remaining: " + msuntilfinished / 1000); //逻辑来设置EditText可以在这里 ｝ onFinish() { mTextField.setText(“完成了!”); ｝ } .start ();

有Rx的纯溶液，有人可能会感兴趣

数字扩展(Double, Float, Long等):

fun Number.countDownTimer(tick: Long = 1, timeUnit: TimeUnit = TimeUnit.SECONDS): Observable<Long> {
    val count = this.toLong()
    return Observable.interval(tick, timeUnit)
        .take(count)
        .map { count - it - 1 }
}

使用

60.countDownTimer().subscribe { textView.text = it }

只需通过传递秒和textview对象调用下面的函数

public void reverseTimer(int Seconds,final TextView tv){

    new CountDownTimer(Seconds* 1000+1000, 1000) {

        public void onTick(long millisUntilFinished) {
            int seconds = (int) (millisUntilFinished / 1000);
            int minutes = seconds / 60;
            seconds = seconds % 60;
            tv.setText("TIME : " + String.format("%02d", minutes)
                    + ":" + String.format("%02d", seconds));
        }

        public void onFinish() {
            tv.setText("Completed");
        }
    }.start();
}

我用kotlin流实现了一个很酷的定时器方法，所以你可以在ViewModel中实现它

    var countDownInit = 30
    fun countDownTimer() = flow<Int> {
    var time = countDownInit
    emit(time)
    while (true){
        time--
        delay(1000L)
        countDownInit = time
        emit(time)
    }
}

然后在你的activity或fragment中像这样调用这个函数

lifecycleScope.launch {
        lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED){
                 viewModel.countDownTimer().collect{time->
                      //and update UI 
                     //and for the finish section you can just use this
                     this.cancel()          
                 }
        }
}

现在在应用程序生命周期的暂停阶段会出现崩溃，你总是有最新的时间

接口方式。

import android.os.CountDownTimer;

/**
 * Created by saikiran on 07-03-2016.
 */
public class CountDownTimerCustom extends CountDownTimer {

    private TimeTickListener mTickListener;
    private TimeFinishListener mFinishListener;
    private long millisUntilFinished;

    public CountDownTimerCustom(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);

    }

    public void updateTickAndFinishListener(TimeTickListener tickListener) {
        mTickListener = tickListener;
    }

    public void updateFinishListner(TimeFinishListener listener) {
        mFinishListener = listener;
    }

    public long getCurrentMs() {
        return millisUntilFinished;
    }

    public int getCurrentSec() {
        return (int) millisUntilFinished / 1000;
    }

    @Override
    public void onTick(long millisUntilFinished) {
        this.millisUntilFinished = millisUntilFinished;
        if (mTickListener != null)
            mTickListener.onTick(millisUntilFinished);
    }

    @Override
    public void onFinish() {
        if (mTickListener != null)
            mTickListener.onFinished();
        mFinishListener.onFinished();
    }


    public interface TimeTickListener {
        void onTick(long mMillisUntilFinished);

        void onFinished();
    }

    public interface TimeFinishListener {
        void onFinished();
    }
}