有问题的if-Statement

Question

我曾经尝试过两三次问这个问题,但未能正确分阶段,所以我想再试一次.我正在制作一个训练秒表应用程序.该应用程序的功能是计算10秒,让受训者10秒准备.一旦该时间过去,它将计入20秒,其中受训者在20秒内进行艰苦锻炼.之后,休息时间为10秒.然后它循环回到20秒的训练并继续这个循环8轮.

我的问题是,它将开始10秒准备,但然后它循环回到10秒计时器.出于某种原因,我的if else语句会循环回到准备时间.我正在使用秒表和时间跨度来表达if语句.

private void timer_Tick(object sender, EventArgs e)
    {
        //throw new NotImplementedException();
        //timer timespan is more than zero, start stopwatch(get the prepare counter going)
        if (timerWatch.Elapsed < new TimeSpan(0, 0, 11))// if its 5sec
        {
            milllisecond = timerWatch.ElapsedMilliseconds;
            second = milllisecond / 1000;
            milllisecond = milllisecond % 1000;
            minute = second / 60;
            second = second % 60;
            hour = minute / 60;
            minute = minute % 60;
            txtblTime.Text = minute.ToString("00") + ":" + second.ToString("00");
        }
        else if (timerWatch.Elapsed >= new TimeSpan(0, 0, 10) && timerWatch.Elapsed < new TimeSpan(0, 0, 21))//more than 4sec
        {
            timerWatch.Restart();

            milllisecond = timerWatch.ElapsedMilliseconds;
            second = milllisecond / 1000;
            milllisecond = milllisecond % 1000;
            minute = second / 60;
            second = second % 60;
            hour = minute / 60;
            minute = minute % 60;
            txtblTime.Text = minute.ToString("00") + ":" + second.ToString("00");

            txtblPrepare.Visibility = System.Windows.Visibility.Collapsed;
            txtblGo.Visibility = System.Windows.Visibility.Visible;
        }
        else if (timerWatch.Elapsed < new TimeSpan(0, 0, 21))
        {
            timerWatch.Restart();

            milllisecond = timerWatch.ElapsedMilliseconds;
            second = milllisecond / 1000;
            milllisecond = milllisecond % 1000;
            minute = second / 60;
            second = second % 60;
            hour = minute / 60;
            minute = minute % 60;

            txtblTime.Text = minute.ToString("00") + ":" + second.ToString("00");
            txtblGo.Visibility = System.Windows.Visibility.Collapsed;
        }
        else
            txtblTime.Text = "Times Up!";                    
    }

Answer 1

您要实现的是所谓的有限状态机.通过计时器推断该机器的状态使得难以理解和读取代码.我会以更直接的方式存储州.正如Plutonix所说,使用枚举

public enum TrainingState
{
    Stopped, // The state machine is not working yet or has finished its work.
    Preparing,
    Working,
    Resting
}

此外,您将需要一个计数器的循环次数

private TrainingState _state = TrainingState.Stopped;
private int _roundNo;

现在你可以像这样制定状态转换

private void ChangeState()
{
    switch (_state) {
        case  TrainingState.Stopped:
            //TODO: Initialize and start the timer, display state
            _state = TrainingState.Preparing;
            break;
        case  TrainingState.Preparing:
            //TODO: Adjust timer intervall for working phase, display state
            _roundNo = 1; // We are going into the first round
           _state = TrainingState.Working;
            break;
        case  TrainingState.Working:
             //TODO: Adjust timer intervall for resting phase, display state
            _state = TrainingState.Resting;
            break;
        case  TrainingState.Resting:
            if (_roundNo == 8) {
                _state = TrainingState.Stopped;
                //TODO: stop timer, display state
            } else {
                //TODO: Adjust timer intervall for working phase, display state
                _roundNo++; // We are going into the next round
               _state = TrainingState.Working;
            }
            break;
    }
}

你必须在开始和里面时调用这个方法timer_Tick.

private void timer_Tick(object sender, EventArgs e)
{
    ChangeState();
}

private void btnStart_Click(object sender, EventArgs e)
{
    ChangeState();
}