下面是我在Kotlin中使用的解决方案

private fun startTimer()
{
    Log.d(TAG, ":startTimer: timeString = '$timeString'")

    object : CountDownTimer(TASK_SWITCH_TIMER, 250)
    {
        override fun onTick(millisUntilFinished: Long)
        {
            val secondsUntilFinished : Long = 
            Math.ceil(millisUntilFinished.toDouble()/1000).toLong()
            val timeString = "${TimeUnit.SECONDS.toMinutes(secondsUntilFinished)}:" +
                    "%02d".format(TimeUnit.SECONDS.toSeconds(secondsUntilFinished))
            Log.d(TAG, ":startTimer::CountDownTimer:millisUntilFinished = $ttlseconds")
            Log.d(TAG, ":startTimer::CountDownTimer:millisUntilFinished = $millisUntilFinished")
        }

        @SuppressLint("SetTextI18n")
        override fun onFinish()
        {
            timerTxtVw.text = "0:00"
            gameStartEndVisibility(true)
        }
    }.start()
}

var futureMinDate = Date()
val sdf = SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH)
try {
    futureMinDate = sdf.parse("2019-08-22")
} catch (e: ParseException) {
    e.printStackTrace()
}

// Here futureMinDate.time Returns the number of milliseconds since January 1, 1970, 00:00:00 GM
// So we need to subtract the millis from current millis to get actual millis
object : CountDownTimer(futureMinDate.time - System.currentTimeMillis(), 1000) {
    override fun onTick(millisUntilFinished: Long) {
        val sec = (millisUntilFinished / 1000) % 60
        val min = (millisUntilFinished / (1000 * 60)) % 60
        val hr = (millisUntilFinished / (1000 * 60 * 60)) % 24
        val day = ((millisUntilFinished / (1000 * 60 * 60)) / 24).toInt()
        val formattedTimeStr = if (day > 1) "$day days $hr : $min : $sec"
        else "$day day $hr : $min : $sec"
        tvFlashDealCountDownTime.text = formattedTimeStr
    }

    override fun onFinish() {
        tvFlashDealCountDownTime.text = "Done!"
    }
}.start()

传递一个未来日期并将其转换为毫秒。

public class Scan extends AppCompatActivity {
int minute;
long min;
TextView tv_timer;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_scan2);
    tv_timer=findViewById(R.id.tv_timer);
    minute=Integer.parseInt("Your time in string form like 10");
    min= minute*60*1000;
    counter(min);
}
private void counter(long min) {
    CountDownTimer timer = new CountDownTimer(min, 1000) {
        public void onTick(long millisUntilFinished) {
            int seconds = (int) (millisUntilFinished / 1000) % 60;
            int minutes = (int) ((millisUntilFinished / (1000 * 60)) % 60);
            int hours = (int) ((millisUntilFinished / (1000 * 60 * 60)) % 24);
            tv_timer.setText(String.format("%d:%d:%d", hours, minutes, seconds));
        }
        public void onFinish() {
            Toast.makeText(getApplicationContext(), "Your time has been completed",
                    Toast.LENGTH_LONG).show();
        }
    };
    timer.start();
}

}

输出:01:30

new CountDownTimer(90000, 1000) {

            public void onTick(long duration) {
                //tTimer.setText("seconds remaining: " + millisUntilFinished / 1000);
                //here you can have your logic to set text to edittext resource id
                // Duration
                long Mmin = (duration / 1000) / 60;
                long Ssec = (duration / 1000) % 60;
                if (Ssec < 10) {
                    tTimer.setText("" + Mmin + ":0" + Ssec);
                } else tTimer.setText("" + Mmin + ":" + Ssec);
            }

            public void onFinish() {
                tTimer.setText("00:00");
            }

        }.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 }

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 ();