如何在控件外部单击时关闭Silverlight中的弹出窗口？

Question

在我的Silverlight UI中,我有一个按钮,当单击时会弹出一个带有一些过滤参数的控件.当你在它外面点击时,我希望这个控件隐藏起来.换句话说,它应该以类似于组合框的方式运行,但它不是组合框(您不选择其中的项目).这是我试图捕获控件之外的点击以解除它的方式:

public partial class MyPanel : UserControl
{
    public MyPanel()
    {
        InitializeComponent();
    }

    private void FilterButton_Click(object sender, RoutedEventArgs e)
    {
        // Toggle the open state of the filter popup
        FilterPopup.IsOpen = !FilterPopup.IsOpen;
    }

    private void UserControl_Loaded(object sender, RoutedEventArgs e)
    {
        // Capture all clicks and close the popup
        App.Current.RootVisual.MouseLeftButtonDown += delegate {
            FilterPopup.IsOpen = false; };
    }
}

不幸的是,事件处理程序MouseLeftButtonDown永远不会被触发.是否有一种成熟的方法可以使弹出控件在你点击它之外时自动解除？如果没有,为什么我的MouseLeftButtonDown处理程序没有解雇？

解:

我想我会发布我的整个解决方案,以防其他人觉得它有用.在我的顶级视觉中,我为弹出窗口声明了一个"盾牌",如下所示:

<UserControl xmlns:my="clr-namespace:Namespace"
    x:Class="Namespace.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation" 
    xmlns:uriMapper="clr-namespace:System.Windows.Navigation;assembly=System.Windows.Controls.Navigation"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
>
  <Grid Background="Black" HorizontalAlignment="Stretch" 
          VerticalAlignment="Stretch">
    <my:MyStuff/>
    <Canvas HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
            x:Name="PopupShield" Background="Transparent" Width="Auto" 
            Height="Auto" Visibility="Collapsed"/>
  </Grid>
</UserControl>

然后,我为Popup类添加了一个扩展方法,如下所示:

public static class PopupUtils
{
    public static void MakeAutoDismissing(this Popup popup)
    {
        var shield = (App.Current.RootVisual as MainPage).PopupShield;

        // Whenever the popup opens, deploy the shield
        popup.HandlePropertyChanges(
            "IsOpen",
            (s, e) =>
            {
                shield.Visibility = (bool)e.NewValue 
                    ? Visibility.Visible : Visibility.Collapsed;
            }
        );

        // Whenever the shield is clicked, dismiss the popup
        shield.MouseLeftButtonDown += (s, e) => popup.IsOpen = false;
    }
}

public static class FrameworkUtils
{
    public static void HandlePropertyChanges(
        this FrameworkElement element, string propertyName, 
        PropertyChangedCallback callback)
    {
        //Bind to a depedency property
        Binding b = new Binding(propertyName) { Source = element };
        var prop = System.Windows.DependencyProperty.RegisterAttached(
            "ListenAttached" + propertyName,
            typeof(object),
            typeof(UserControl),
            new System.Windows.PropertyMetadata(callback));

        element.SetBinding(prop, b);
    }
}

扩展方法使用如下:

private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
    FilterPopup.MakeAutoDismissing();
}

Answer 1

一种方法是将控件放在填充整个Silverlight表面的透明画布上.单击画布时,关闭画布并控制.如果要接收鼠标事件,确保将画布的背景画笔设置为"透明"非常重要.

我没有成功的另一种方法是在Silverlight中使用鼠标捕获并检测何时在弹出窗口外单击鼠标.

Answer 2

您是否在 RootVisual 上设置了背景颜色？