问题描述

在我的 Silverlight UI 中，我有一个按钮，单击该按钮会弹出一个带有一些过滤参数的控件.我希望这个控件在您单击它外部时隐藏起来.换句话说，它应该以类似于组合框的方式起作用，但它不是组合框(您不选择其中的项目).以下是我尝试捕获控件外部的单击以将其关闭的方式:

In my Silverlight UI, I have a button that when clicked pops up a control with some filtering parameters. I would like this control to hide itself when you click outside of it. In other words, it should function in a manner similar to a combo box, but it's not a combo box (you don't select an item in it). Here's how I'm trying to capture a click outside of the control to dismiss it:

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，MouseLeftButtonDown 的事件处理程序永远不会被触发.是否有一种成熟的方法可以制作弹出控件，当您在外部单击时自动关闭?如果没有，为什么我的 MouseLeftButtonDown 处理程序没有触发?

Unfortunately, the event handler for MouseLeftButtonDown is never getting fired. Is there a well-established way of making a popup control that auto-dismisses when you click outside of it? If not, why isn't my MouseLeftButtonDown handler firing?

解决方案:

我想我会发布我的整个解决方案，以防其他人发现它有帮助.在我的顶级视觉效果中，我为弹出窗口声明了一个盾牌"，如下所示:

I thought I'd post my entire solution in case others find it helpful. In my top-level visual, I declare a "shield" for the popups, like this:

<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:

Then, I added an extension method for the Popup class, like this:

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);
    }
}

扩展方法是这样使用的:

The extension method is used like this:

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

推荐答案

你给你的 RootVisual 设置了背景颜色吗?

Did you set a background color on your RootVisual?

这篇关于在控件外部单击时如何关闭 Silverlight 中的弹出窗口?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！