c# - 如何在 WPF 中订阅上下文菜单关闭事件？

Question

我尝试了各种解决方案，例如发现的 here ，其接受的答案如下:

<Button ContextMenuClosing="ContextMenu_ContextMenuClosing">
    <Button.ContextMenu>
        <ContextMenu>
             <MenuItem Header="Go"/>
        </ContextMenu>
    </Button.ContextMenu>
 </Button>

但是，在实现上述解决方案后，我仍然无法成功监听 ContextMenuClosing 事件，无论它如何关闭(进行选择、单击父按钮、单击菜单或按钮外的任何位置)。下面是我的代码，我做错了什么？

测试页.xaml

<Page x:Class="MyProject.pages.TestPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:MIMOUI.pages"
    mc:Ignorable="d"
    d:DesignHeight="300"
    d:DesignWidth="300"
    Title="TestPage">

    <Grid>
        <Button x:Name="myMenuButton" 
            Width="140" 
            Height="100" 
            Click="myMenuButton_Click"
            ContextMenuClosing="myMenuButton_ContextMenuClosing"
            Background="NavajoWhite" 
            Foreground="BurlyWood">

            <Button.ContextMenu>
                <ContextMenu x:Name="myMenuButton_ContextMenu" Width="250">
                    <MenuItem x:Name="myTaskMenuButton" Header="TASKS" />
                    <MenuItem x:Name="myTransactionButton" Header="TRANSACTION" />
                    <MenuItem x:Name="mySetupMenuButton" Header="SETUP" />
                </ContextMenu>
            </Button.ContextMenu>
        </Button>
    </Grid>
</Page>

TestPage.xaml.cs

using System;
using System.Windows;
using System.Windows.Controls;

namespace MyProject.pages {
    public partial class TestPage : Page {
        public TestPage() {
            InitializeComponent();
        }

        public void myMenuButton_Click(object sender, RoutedEventArgs e) {
            (sender as Button).ContextMenu.IsOpen = true;
        }

        public void myMenuButton_ContextMenuClosing(object sender, RoutedEventArgs e) {
            Console.WriteLine("intercepted!!!!");
            e.Handled = true;
        }
    }
}

Answer 1

出于我未知的原因，当您的 Click 代码打开它时，ContextMenuClosing 似乎不会被触发。如果您通过右键单击按钮打开ContextMenu，则会按预期触发事件。作为解决方法，您可以使用 ContextMenu.Closed似乎在这两种情况下都调用了事件

<Button x:Name="myMenuButton" Click="myMenuButton_Click" ...>
    <Button.ContextMenu>
        <ContextMenu ... Closed="myMenuButton_ContextMenu_Closed">
            <MenuItem x:Name="myTaskMenuButton" Header="TASKS" />
            <MenuItem x:Name="myTransactionButton" Header="TRANSACTION" />
            <MenuItem x:Name="mySetupMenuButton" Header="SETUP" />
        </ContextMenu>
    </Button.ContextMenu>
</Button>

并在您的代码中

private void myMenuButton_ContextMenu_Closed(object sender, RoutedEventArgs e)
{
    Debug.WriteLine("myMenuButton_ContextMenu_Closed");
}

唯一的区别似乎是您无法像在 ContextMenuClosing 事件中那样阻止 ContextMenu 关闭