Question

请允许我说,如果用户选择一个称为“重复”的Box公司,那么我就想再说一个功能,但是,当用户 un弄Box时,对该功能的电话应当停止。

我利用支票、Click和Tap事件进行了审判,但一开始,检查箱就没有任何变化。

我甚至试图在另一个纽顿的“Click”方法内使用一个 lo子,但后来却在布顿的受压状态上制造了一个锁。

任何想法/替代建议?

Answer 1

Don t use a loop, use a timer andchange it on and offing on theeck Box state.

    // your loop replacement: a timer
    Timer timer;

    // this method is called periodically by the timer - do whatever you want here
    // but make sure you use proper dispatching when accessing the UI (!)
    private void MyTimerCallback(object state)
    {
        System.Diagnostics.Debug.WriteLine("Action!");
    }

    // this creates and starts the timer
    private void StartTimer()
    {
        // set the timer to call your function every 500ms
        timer = new Timer(MyTimerCallback, null, 500, 500);
    }

    // stop the timer
    private void StopTimer()
    {
        timer.Dispose();
    }

    // Checked handler for the checkbox: start the timer
    private void checkBox1_Checked(object sender, RoutedEventArgs e)
    {
        StartTimer();
    }

    // Unchecked handler for the checkbox: stop the timer
    private void checkBox1_Unchecked(object sender, RoutedEventArgs e)
    {
        StopTimer();
    }

Some notes about the callback ("MyTimerCallback"):

The method does not execute on the thread that created the timer; it executes on a ThreadPool thread that is supplied by the system. (Source: Documentation of Timer)

这一点很重要,告诉你不要从这种方法中直接接触任何情报和安全局要素。相反的:

textBlock1.Dispatcher.BeginInvoke(() => { textBlock1.Text = "Changed text"; });

Answer 2

Spinning in a loop on the UI thread is bad practice. Why not bind to a dependency property instead and then do what you need in the PropertyChangedCallback?

XAML

<!-- MainWindowInstance is the x:Name of this class, you can avoid setting the -->
<!-- ElementName if you setup a DataContext -->
<CheckBox Content="Repeat" IsChecked="{Binding ElementName=MainWindowInstance, Path=Checked, Mode=TwoWay}" />

法典背后

public bool Checked
{
   get { return (bool)GetValue(CheckedProperty); }
   set { SetValue(CheckedProperty, value); }
}

public static readonly DependencyProperty CheckedProperty = DependencyProperty.Register("Checked", typeof(bool), typeof(MainPage), new PropertyMetadata((s, e) =>
{
   if ((bool)e.NewValue)
   {
      // Checked
      MessageBox.Show("checkbox checked");
   }
   else
   {
      // Unchecked
   }
}));

友情链接