互斥辨认的菜单项？ [英] Mutually exclusive checkable menu items?

问题描述

由于以下code：

<MenuItem x:Name="MenuItem_Root" Header="Root">
    <MenuItem x:Name="MenuItem_Item1" IsCheckable="True" Header="item1" />
    <MenuItem x:Name="MenuItem_Item2" IsCheckable="True" Header="item2"/>
    <MenuItem x:Name="MenuItem_Item3" IsCheckable="True" Header="item3"/>
</MenuItem>

在XAML中，有没有一种方法来创建可勾选菜单项的互相排斥？用户在哪里检查项目2，项目的1和3是自动选中。

In XAML, is there a way to create checkable menuitem's that are mutually exclusive? Where is the user checks item2, item's 1 and 3 are automatically unchecked.

我可以通过监控点击事件的菜单上，确定哪些项目进行检查，取消选中其他菜单项中的code实现这一目标的背后。我想有一个更简单的方法。

I can accomplish this in the code behind by monitoring the click events on the menu, determining which item was checked, and unchecking the other menuitems. I'm thinking there is an easier way.

任何想法？

推荐答案

这可能不是你要找的东西，但你可以写一个扩展菜单项类，允许您使用类似的单选类的<​​code>组名属性。我稍微修改这获取同样延长切换按钮控制和整顿它一点您的具体情况以及与此想出了：

This may not be what you're looking for, but you could write an extension for the MenuItem class that allows you to use something like the GroupName property of the RadioButton class. I slightly modified this handy example for similarly extending ToggleButton controls and reworked it a little for your situation and came up with this:

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;

namespace WpfTest
{
     public class MenuItemExtensions : DependencyObject
     {
           public static Dictionary<MenuItem, String> ElementToGroupNames = new Dictionary<MenuItem, String>();

           public static readonly DependencyProperty GroupNameProperty =
               DependencyProperty.RegisterAttached("GroupName",
                                            typeof(String),
                                            typeof(MenuItemExtensions),
                                            new PropertyMetadata(String.Empty, OnGroupNameChanged));

           public static void SetGroupName(MenuItem element, String value)
           {
                element.SetValue(GroupNameProperty, value);
           }

           public static String GetGroupName(MenuItem element)
           {
                return element.GetValue(GroupNameProperty).ToString();
           }

           private static void OnGroupNameChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
           {
                //Add an entry to the group name collection
                var menuItem = d as MenuItem;

                if (menuItem != null)
                {
                     String newGroupName = e.NewValue.ToString();
                     String oldGroupName = e.OldValue.ToString();
                     if (String.IsNullOrEmpty(newGroupName))
                     {
                          //Removing the toggle button from grouping
                          RemoveCheckboxFromGrouping(menuItem);
                     }
                     else
                     {
                          //Switching to a new group
                          if (newGroupName != oldGroupName)
                          {
                              if (!String.IsNullOrEmpty(oldGroupName))
                              {
                                   //Remove the old group mapping
                                   RemoveCheckboxFromGrouping(menuItem);
                              }
                              ElementToGroupNames.Add(menuItem, e.NewValue.ToString());
                               menuItem.Checked += MenuItemChecked;
                          }
                     }
                }
           }

           private static void RemoveCheckboxFromGrouping(MenuItem checkBox)
           {
                ElementToGroupNames.Remove(checkBox);
                checkBox.Checked -= MenuItemChecked;
           }


           static void MenuItemChecked(object sender, RoutedEventArgs e)
           {
                var menuItem = e.OriginalSource as MenuItem;
                foreach (var item in ElementToGroupNames)
                {
                     if (item.Key != menuItem && item.Value == GetGroupName(menuItem))
                     {
                          item.Key.IsChecked = false;
                     }
                }
           }
      }
 }

然后，在XAML中，你会写：

Then, in the XAML, you'd write:

        <MenuItem x:Name="MenuItem_Root" Header="Root">
            <MenuItem x:Name="MenuItem_Item1" YourNamespace:MenuItemExtensions.GroupName="someGroup" IsCheckable="True" Header="item1" />
            <MenuItem x:Name="MenuItem_Item2" YourNamespace:MenuItemExtensions.GroupName="someGroup" IsCheckable="True" Header="item2"/>
            <MenuItem x:Name="MenuItem_Item3" YourNamespace:MenuItemExtensions.GroupName="someGroup" IsCheckable="True" Header="item3"/>
        </MenuItem>

这是一个有点痛，但它提供了不强迫你写任何额外程序code的振作（从扩展类不谈，当然）来实现它。

It's a bit of a pain, but it offers the perk of not forcing you to write any additional procedural code (aside from the extension class, of course) to implement it.

幸得布拉德·坎宁安谁编写了原始的切换按钮解决方案。

Credit goes to Brad Cunningham who authored the original ToggleButton solution.

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