问如何在Android中设置倒计时计时器？

EN

    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()