Question

我在这里有一个项目，它默认设置了MouseEnter事件发生的操作。我的意思是，打开一个Window，关闭，返回等等，只能通过MouseEnter事件发生。

我被要求在3秒后使事件发生火灾。这意味着用户将鼠标放在控件上，并且仅在3秒后，窗口中的所有控件都必须发生事件。

所以，我想到了一个全局计时器或类似的东西，它会返回假，直到计时器达到3 ......我认为这就是......

Geez，有谁知道我该怎么做？

谢谢！

Answer 1

您可以定义一个类，该类将公开接收要执行的操作的DelayedExecute方法，并根据延迟执行的需要创建计时器。它看起来像这样：

public static class DelayedExecutionService
{
    // We keep a static list of timers because if we only declare the timers
    // in the scope of the method, they might be garbage collected prematurely.
    private static IList<DispatcherTimer> timers = new List<DispatcherTimer>();

    public static void DelayedExecute(Action action, int delay = 3)
    {
        var dispatcherTimer = new System.Windows.Threading.DispatcherTimer();

        // Add the timer to the list to avoid it being garbage collected
        // after we exit the scope of the method.
        timers.Add(dispatcherTimer);

        EventHandler handler = null;
        handler = (sender, e) =>
        {
            // Stop the timer so it won't keep executing every X seconds
            // and also avoid keeping the handler in memory.
            dispatcherTimer.Tick -= handler;
            dispatcherTimer.Stop();

            // The timer is no longer used and shouldn't be kept in memory.
            timers.Remove(dispatcherTimer);

            // Perform the action.
            action();
        };

        dispatcherTimer.Tick += handler;
        dispatcherTimer.Interval = TimeSpan.FromSeconds(delay);
        dispatcherTimer.Start();
    }
}

然后你可以这样称呼它：

DelayedExecutionService.DelayedExecute(() => MessageBox.Show("Hello!"));

或

DelayedExecutionService.DelayedExecute(() => 
{
    DoSomething();
    DoSomethingElse();
});

Answer 2

我只是想添加一个更简单的解决方案：

public static void DelayedExecute(Action action, int delay = 3000)
{
    Task.Factory.StartNew(() => 
    {
        Thread.Sleep(delay);
        action();
    }
}

然后像this other answer

一样使用它

用于触发事件WPF的计时器

2 个答案: