将事件处理程序分配给以自定义样式定义的 ContextMenu 项

Question

我创建了带有预定义菜单项的上下文菜单样式：

    <Style TargetType="{x:Type ContextMenu}" x:Key="DataGridColumnFilterContextMenu">                
                <Setter Property="ContextMenu.Template">
                <Setter.Value>
                    <ControlTemplate>
                        <Border BorderBrush="#868686"
                                BorderThickness="1"
                                Background="#FAFAFA"> 
                                <Grid MaxHeight="500">
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="Auto"/>
                                    <RowDefinition Height="*"/>
                                </Grid.RowDefinitions>
                                <StackPanel>
                                    <MenuItem Header="Filtrēt" StaysOpenOnClick="True" Name="DynSearch">
                                        <MenuItem.Icon>
                                            <Image   RenderOptions.BitmapScalingMode="NearestNeighbor"
                                                     RenderOptions.EdgeMode="Aliased" 
                                                     Source="/Furniture;component/Resources/search4.png" />
                                        </MenuItem.Icon>
                                    </MenuItem>
                                    <Separator  Margin="20 5 20 0"  Height="2" Width="Auto" />
                                    <MenuItem Margin="5 5 0 0" StaysOpenOnClick="True" >
                                        <MenuItem.Template>
                                            <ControlTemplate >
                                                <CheckBox Padding="15 0 0 0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >Iezīmēt/Atzīmēt visus</CheckBox>
                                            </ControlTemplate>
                                        </MenuItem.Template>
                                        <MenuItem.Icon>
                                            <Image   RenderOptions.BitmapScalingMode="NearestNeighbor"
                                                     RenderOptions.EdgeMode="Aliased" 
                                                     Source="/Furniture;component/Resources/search4.png" />
                                        </MenuItem.Icon>
                                    </MenuItem>
                                    <Separator Margin="20 5 20 0" Height="2" Width="Auto" />
                                    <RadioButton Margin="5 5 0 0" Padding="15 0 0 0" GroupName="Sorting" Content="Augoša secībā" IsChecked="True"/>
                                    <RadioButton Margin="5 5 0 0" Padding="15 0 0 0" GroupName="Sorting" Content="Dilstoša secībā" />
                                    <Separator Margin="20 5 20 5" Height="2" Width="Auto" />
                                </StackPanel>
                                <ScrollViewer Grid.Row="1" 
                                              Margin="1,0,1,0"                                            
                                              CanContentScroll="True"
                                              VerticalScrollBarVisibility="Auto"
                                              Grid.ColumnSpan="2">
                                        <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Cycle" />
                                    </ScrollViewer>
                                </Grid>                              
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

现在我将样式分配给新的 ContextMenu，并想将 Click 事件处理程序分配给在 header "Filtrēt" 样式中定义的 MenuItem。我试过这样做：

ContextMenu cm = new ContextMenu();
cm.Style = Application.Current.Resources["DataGridColumnFilterContextMenu"] as Style;
var controlList = ((((cm.Template.LoadContent() as Border).Child as Grid).Children)[0] as StackPanel).Children;
MenuItem filterItem = (controlList[0] as MenuItem);
filterItem.Click += MiFiltre_Click;

而当我点击 debugger 时，它并没有进入 MiFiltre_Click 方法。我尝试了不同的事件，例如 MouseDown 和 PreviewMouseDown。我也尝试绑定 ICommand，但这也没有用。

然后我搜索了这个问题并意识到 cm.Template.LoadContent() 实际上可能会创建我的 ContextMenu 模板的新实例，我正试图将我的事件处理程序绑定到不同的控件实例。然后我尝试使用 VisualTreeHelper 和 LogicalTreeHelper 获取 ContextMenu 节点控件，但这也没有用。

所以这里有问题：

如何实现Click事件处理器绑定？
如果第一题太很难，那么如何定义 ContextMenu 子项的当前实例自定义样式？

Answer 1

我假设此菜单样式是在名为 "MyResources.xaml" 的资源字典中定义的。

在同一项目文件夹中创建一个Class文件，并将其命名为"MyResources.xaml.cs"。

像这样使其成为部分 class：

namespace WhateverNamespace
{
    public partial class MyResources
    {
        private void FilterMenuItem_Click(object sender, RoutedEventArgs e)
        {
            MenuItem mi = (MenuItem)sender;

            //  Below, PlacementTarget is the control the user right-clicked on. 
            //  Use that directly if you want that instead of its viewmodel. 

            //  This works with the conventional ContextMenu defined below.
            //ViewModel viewModel = ((FrameworkElement)((ContextMenu)mi.Parent).PlacementTarget).DataContext as ViewModel;

            //  This works with your template design. The only difference is 
            //  TemplatedParent instead of Parent. 
            ViewModel viewModel = 
                ((FrameworkElement)((ContextMenu)mi.TemplatedParent).PlacementTarget)
                .DataContext as ViewModel;

            MessageBox.Show("FilterMenuItem_Click");
        }
    }
}

给资源字典一个x:Class属性：

<ResourceDictionary 
    x:Class="WhateverNamespace.MyResources"

连接处理程序：

<MenuItem 
    Click="FilterMenuItem_Click"
    Header="Filtrēt" 
    StaysOpenOnClick="True" 
    Name="DynSearch">

顺便说一下，您不需要乱用样式和模板来创建 ContextMenu 资源：

<ContextMenu x:Key="DataGridColumnFilterContextMenu">
    <MenuItem 
        Click="FilterMenuItem_Click"
        Header="Filtrēt" 
        StaysOpenOnClick="True" 
        Name="DynSearch">
        <MenuItem.Icon>
            <Image
                RenderOptions.BitmapScalingMode="NearestNeighbor"
                RenderOptions.EdgeMode="Aliased" 
                Source="/Furniture;component/Resources/search4.png"
                />
        </MenuItem.Icon>
    </MenuItem>
    <Separator />
    <MenuItem StaysOpenOnClick="True">
        <MenuItem.Header>
            <CheckBox>Iezīmēt/Atzīmēt visus</CheckBox>
        </MenuItem.Header>
        <MenuItem.Icon>
            <Image   
                RenderOptions.BitmapScalingMode="NearestNeighbor"
                RenderOptions.EdgeMode="Aliased" 
                Source="/Furniture;component/Resources/search4.png"
                />
        </MenuItem.Icon>
    </MenuItem>
    <Separator />
    <MenuItem>
        <MenuItem.Header>
            <RadioButton GroupName="Sorting" Content="Augoša secībā" IsChecked="True"/>
        </MenuItem.Header>
    </MenuItem>
    <MenuItem>
        <MenuItem.Header>
            <RadioButton GroupName="Sorting" Content="Dilstoša secībā" IsChecked="True"/>
        </MenuItem.Header>
    </MenuItem>
</ContextMenu>

将事件处理程序分配给以自定义样式定义的 ContextMenu 项

Assign event handler to ContextMenu item defined in custom style

wpf

contextmenu

datatemplate