在OnClickListener内，如何使用不同的参数多次使函数有趣前一个完成后要运行的功能

如何解决在OnClickListener内，如何使用不同的参数多次使函数有趣前一个完成后要运行的功能

希望有人可以提供帮助。就像标题中所说的那样，在一个按钮onclick侦听器中，我试图运行一个倒数计时器三次，每次倒数计时器要在前一个结束后才能运行。

然后我需要根据套数等重复多次。 我已经尝试了很多事情，同步startTimer（x）函数，ReentrantLock，boolean isComplete变量，3个连接的线程，GlobalScope.launch与join（），但是每次计时器都同时启动时。 谁能提出解决方案？ 谢谢！

override fun onClick(view: View?) {
//... other view click code...
R.id.btn_timer_startWorkout -> {
            val thrdA = Thread {
                // run prep time
                var prepTime = et_timer_prep.text.toString().toLong()
                timeInMilliseconds = prepTime.times(1000)
                startTimer(timeInMilliseconds,et_timer_prep)
            }
            val thrdB = Thread {
                // run work timer
                var workTime = et_timer_work.text.toString().toLong()
                timeInMilliseconds = workTime.times(1000)
                startTimer(timeInMilliseconds,et_timer_work)
            }
            val thrdC = Thread {
                // run work timer
                var restTime = et_timer_rest.text.toString().toLong()
                timeInMilliseconds = restTime.times(1000)
                startTimer(timeInMilliseconds,et_timer_rest)
            }
            thrdA.start()
            thrdA.join()
            thrdB.start()
            thrdB.join()
            thrdC.start()
            thrdC.join()
    }


private fun startTimer(prepTime: Long,editText: EditText) {

    countdown_timer = object : CountDownTimer(prepTime,1000) {
        override fun onTick(millisUntilFinished: Long) {
            timeInMilliseconds = millisUntilFinished
            updateUI(timeInMilliseconds,editText)
        }

        override fun onFinish() {
            Toast.makeText(this@TimerActivity,"Finished",Toast.LENGTH_LONG).show()
        }
    }
    countdown_timer.start()
}

解决方法

您的所有线程都在主线程上阻塞，因此直到它们全部完成后才能更新UI。这也可能导致应用程序无响应错误（ANR）。

要在没有协程的情况下执行此操作，您需要回调：

R.id.btn_timer_startWorkout -> {
    var prepTime = et_timer_prep.text.toString().toLong()
    timeInMilliseconds = prepTime.times(1000)
    startTimer(timeInMilliseconds,et_timer_prep) {
        var workTime = et_timer_work.text.toString().toLong()
        timeInMilliseconds = workTime.times(1000)
        startTimer(timeInMilliseconds,et_timer_work) {
            var restTime = et_timer_rest.text.toString().toLong()
            timeInMilliseconds = restTime.times(1000)
            startTimer(timeInMilliseconds,et_timer_rest) {}
        }
    }

}

private inline fun startTimer(prepTime: Long,editText: EditText,callback: () -> Unit) {

    countdown_timer = object : CountDownTimer(prepTime,1000) {
        override fun onTick(millisUntilFinished: Long) {
            timeInMilliseconds = millisUntilFinished
            updateUI(timeInMilliseconds,editText)
        }

        override fun onFinish() {
            Toast.makeText(this@TimerActivity,"Finished",Toast.LENGTH_LONG).show()
            callback()
        }
    }
    countdown_timer.start()
}

协程可以使您摆脱丑陋的嵌套回调。您应该从lifecycleScope而不是GlobalScope启动它们，以便它们可以与UI元素一起使用：

R.id.btn_timer_startWorkout -> {
    lifecycleScope.launch {
        var prepTime = et_timer_prep.text.toString().toLong()
        timeInMilliseconds = prepTime.times(1000)
        startTimer(timeInMilliseconds,et_timer_prep)

        var workTime = et_timer_work.text.toString().toLong()
        timeInMilliseconds = workTime.times(1000)
        startTimer(timeInMilliseconds,et_timer_work)

        var restTime = et_timer_rest.text.toString().toLong()
        timeInMilliseconds = restTime.times(1000)
        startTimer(timeInMilliseconds,et_timer_rest) {}
    }
}

private suspend fun startTimer(prepTime: Long,editText: EditText) {
    var elapsed = 0L
    while (elapsed < prepTime) {
        val delay = min(1000L,prepTime - elapsed)
        delay(delay)
        elapsed += delay
        timeInMilliseconds = prepTime - elapsed
        updateUI(timeInMilliseconds,editText)
    }
    Toast.makeText(this@TimerActivity,Toast.LENGTH_LONG).show()
}