Question

我正在尝试使用三个按钮在我的应用程序中实现一个计时器 - 启动，停止和重启。

计时器启动并停止正常。但是，当我点击重启按钮时，它从之前的秒和分钟值开始，而不是从0和0开始。我无法看到我做错了，因为我在开始时将秒和分钟设置为0重启方法本身。

例如：第一次从0开始并继续到1,2,3。停止在3.当我重新启动时，它从2开始并继续到4,6 ...如果我再次重新启动它从3开始并继续到6,9,12 ......

以下是我的代码：

    public int seconds;
    public int minutes;
    public int hours;

    System.Windows.Threading.DispatcherTimer myTimer = new System.Windows.Threading.DispatcherTimer();

    private void Tick_Timer_Start(object sender, RoutedEventArgs e)
    {
        myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1000);
        myTimer.Tick += new EventHandler(Each_Tick);
        myTimer.Start();
    }

    private void Tick_Timer_Stop(object sender, RoutedEventArgs e)
    {
        myTimer.Stop();
    }

    private void Tick_Timer_Restart(object sender, RoutedEventArgs e)
    {
        seconds = 0;
        minutes = 0;
        Timertext.Text = "0 minutes : 0 seconds";
        myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1000);
        myTimer.Tick += new EventHandler(Each_Tick);
        myTimer.Start();

    }

    private void Each_Tick(object o, EventArgs sender)
    {
        seconds = seconds + 1;

        if (seconds < 10 && minutes < 10)
        {
            Timertext.Text =  minutes.ToString() + " minutes : " + seconds.ToString() + " seconds";
        }
        else if (seconds > 59)
        {
            minutes = minutes + 1;
            seconds = 0;
            seconds = seconds + 1;
            Timertext.Text =  minutes.ToString() + " minutes : " + seconds.ToString() + " seconds";
        }
        else
        {
            Timertext.Text =  minutes.ToString() + " minutes : " + seconds.ToString() + " seconds";
        }
    }

非常感谢任何帮助。

Answer 1

您的计划永远不会按预期工作！每次单击开始按钮时，都会向Dispatchertimer添加Tickhandler，以便秒开始增加2然后增加3，依此类推。您必须在Stop和Restart方法中删除Handler！然后所有都按预期工作，您不必在每次重新启动时创建新的DispatcherTimer。顺便说一下，@ DeshDeep Singh的解决方案永远不会收集旧的DispatcherTimer，因为EventHandler不会收集它 - 因此他的解决方案会给你带来很大的内存问题。

以下是工作代码：

public int seconds;
public int minutes;
public int hours;

System.Windows.Threading.DispatcherTimer myTimer = new System.Windows.Threading.DispatcherTimer();

private void Tick_Timer_Start(object sender, RoutedEventArgs e)
{
    myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1000);
    myTimer.Tick += Each_Tick;
    myTimer.Start();
}

private void Tick_Timer_Stop(object sender, RoutedEventArgs e)
{
    myTimer.Tick -= Each_Tick;
    myTimer.Stop();
}

private void Tick_Timer_Restart(object sender, RoutedEventArgs e)
{
    myTimer.Tick -= Each_Tick;
    seconds = 0;
    minutes = 0;
    Timertext.Text = "0 minutes : 0 seconds";
    myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1000);
    myTimer.Tick += new EventHandler(Each_Tick);
    myTimer.Start();
}

private void Each_Tick(object sender, EventArgs e)
{
    seconds = seconds + 1;
    if (seconds < 10 && minutes < 10)
    {
        Timertext.Text = minutes.ToString() + " minutes : " + seconds.ToString() + " seconds";
    }
    else if (seconds > 59)
    {
        minutes = minutes + 1;
        seconds = 0;
        seconds = seconds + 1;
        Timertext.Text = minutes.ToString() + " minutes : " + seconds.ToString() + " seconds";
    }
    else
    {
        Timertext.Text = minutes.ToString() + " minutes : " + seconds.ToString() + " seconds";
    }
}

Answer 2

您需要做的就是仅将Tick处理程序附加：

private int seconds; private int minutes; private int hours; private DispatcherTimer myTimer = new DispatcherTimer(); private void Initialize() { myTimer.Interval = TimeSpan.FromMilliseconds(1000); myTimer.Tick += Each_Tick; } private void Tick_Timer_Start(object sender, RoutedEventArgs e) { myTimer.Start(); } private void Tick_Timer_Stop(object sender, RoutedEventArgs e) { myTimer.Stop(); } private void Tick_Timer_Restart(object sender, RoutedEventArgs e) { myTimer.Stop(); seconds = 0; minutes = 0; Timertext.Text = "0 minutes : 0 seconds"; myTimer.Start(); } private void Each_Tick(object o, EventArgs sender) { ... }

更简单的解决方案是只有Start和Stop，而不需要重启：

private int seconds; private int minutes; private int hours; private DispatcherTimer myTimer = new DispatcherTimer(); private void Initialize() { myTimer.Interval = TimeSpan.FromMilliseconds(1000); myTimer.Tick += Each_Tick; } private void Tick_Timer_Start(object sender, RoutedEventArgs e) { myTimer.Stop(); seconds = 0; minutes = 0; Timertext.Text = "0 minutes : 0 seconds"; myTimer.Start(); } private void Tick_Timer_Stop(object sender, RoutedEventArgs e) { myTimer.Stop(); } private void Each_Tick(object o, EventArgs sender) { ... }

Answer 3

由于计时器未重置，请执行以下操作：

private void Tick_Timer_Restart(object sender, RoutedEventArgs e)
    {
        myTimer = new System.Windows.Threading.DispatcherTimer();

        seconds = 0;
        minutes = 0;
        Timertext.Text = "0 minutes : 0 seconds";
        myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1000);
        myTimer.Tick += new EventHandler(Each_Tick);
        myTimer.Start();

    }

Answer 4

     // put   myTimer.Stop() in Restart Method

   private void Tick_Timer_Restart(object sender, RoutedEventArgs e)
    {
        myTimer.Stop();  // stop timmer here and try
        seconds = 0;
        minutes = 0;
        Timertext.Text = "0 minutes : 0 seconds";
        myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1000);
        myTimer.Tick += new EventHandler(Each_Tick);
        myTimer.Start();

    }

无法正确重新启动DispatcherTimer

4 个答案: