c# - 仅适用于 ListViewItem 的 ContextMenu

Question

我有一个上下文菜单 - 问题是我需要它只在单击 listviewitem 时打开。现在，如果我单击列表视图或标题中的任意位置，它将打开。

<ListView> 
    <ListView.ContextMenu>
        <ContextMenu>
            <MenuItem Header="More Info" Command="{Binding MoreInfo}" />
        </ContextMenu>
     </ListView.ContextMenu>
     <ListView.View> 
         <GridView> 
           <!-- columns and stuff here -->
         </GridView>
     </ListView.View>
 </ListView>

我尝试将 ContextMenu 添加为资源并将其应用为样式，但这会破坏命令（单击更多信息应该打开一个对话框窗口，这种方式不起作用）

<ListView.Resources>
    <ContextMenu x:Key="ItemContextMenu">
        <MenuItem Header="More Info" Command="{Binding MoreInfo}" Background="WhiteSmoke" />
    </ContextMenu>
</ListView.Resources>
<ListView.ItemContainerStyle>
    <Style TargetType="{x:Type ListViewItem}" >
        <Setter Property="ContextMenu" Value="{StaticResource ItemContextMenu}" />
    </Style>
</ListView.ItemContainerStyle>

所以不确定如何将上下文菜单限制为仅 listviewitem 并让命令起作用。

Answer 1

在模板中的命令绑定中使用RelativeSource，它将起作用：

<ListView.Resources>
    <ContextMenu x:Key="ItemContextMenu">
        <MenuItem Header="More Info" Command="{Binding Path=DataContext.MoreInfo, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListView}}" Background="WhiteSmoke" />
    </ContextMenu>
</ListView.Resources>

<ListView.ItemContainerStyle>
    <Style TargetType="{x:Type ListViewItem}" >
        <Setter Property="ContextMenu" Value="{StaticResource ItemContextMenu}" />
    </Style>
</ListView.ItemContainerStyle>

Answer 2

扩展这篇非常有用的帖子...如果您ContextMenu在 a 中有自定义按钮或其他对象ControlTemplate，我已将上面的答案与 Closing ContextMenu with Templated MenuItems的答案结合起来，这样当用户单击时Button，ContextMenu通常只使用 XAML 关闭. 这花了大约 10 个小时才完成。希望它可以节省您的时间。支持 MVVMICommand使用。我还使用 [this post][2] 中的StyleforContextMenu来消除 90 年代的外观。

<ListView.Resources>
    <ContextMenu x:Key="ItemContextMenu" Style="{StaticResource HorizontalContextMenu}">
        <MenuItem>
            <MenuItem.Template>
                <ControlTemplate>
                    <Grid MinHeight="50" MinWidth="50">
                        <Button Style="{StaticResource CloseAppButton}" Command="{Binding Path=DataContext.DeleteCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListView}}" >
                            <Button.Triggers>
                                <EventTrigger RoutedEvent="Button.Click">
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(ContextMenu.IsOpen)" Storyboard.Target="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=ContextMenu}}">
                                                <DiscreteObjectKeyFrame KeyTime="0:0:0">
                                                    <DiscreteObjectKeyFrame.Value>
                                                        <sys:Boolean>False</sys:Boolean>
                                                    </DiscreteObjectKeyFrame.Value>
                                                </DiscreteObjectKeyFrame>
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </BeginStoryboard>
                                </EventTrigger>
                            </Button.Triggers>
                        </Button>
                    </Grid>
                </ControlTemplate>
            </MenuItem.Template>
        </MenuItem>

        <MenuItem>
            <MenuItem.Template>
                <ControlTemplate>
                    <Grid MinHeight="50" MinWidth="50">
                        <Button Style="{StaticResource AddButton}" Command="{Binding Path=DataContext.TestCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListView}}" >
                            <Button.Triggers>
                                <EventTrigger RoutedEvent="Button.Click">
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(ContextMenu.IsOpen)" Storyboard.Target="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=ContextMenu}}">
                                                <DiscreteObjectKeyFrame KeyTime="0:0:0">
                                                    <DiscreteObjectKeyFrame.Value>
                                                        <sys:Boolean>False</sys:Boolean>
                                                    </DiscreteObjectKeyFrame.Value>
                                                </DiscreteObjectKeyFrame>
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </BeginStoryboard>
                                </EventTrigger>
                            </Button.Triggers>
                        </Button>
                    </Grid>
                </ControlTemplate>
            </MenuItem.Template>
        </MenuItem>

        <MenuItem>
            <MenuItem.Template>
                <ControlTemplate>
                    <Grid MinHeight="50" MinWidth="50">
                        <Button Style="{StaticResource PluginInfoButton}" Command="{Binding Path=DataContext.TestCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListView}}" >
                            <Button.Triggers>
                                <EventTrigger RoutedEvent="Button.Click">
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(ContextMenu.IsOpen)" Storyboard.Target="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=ContextMenu}}">
                                                <DiscreteObjectKeyFrame KeyTime="0:0:0">
                                                    <DiscreteObjectKeyFrame.Value>
                                                        <sys:Boolean>False</sys:Boolean>
                                                    </DiscreteObjectKeyFrame.Value>
                                                </DiscreteObjectKeyFrame>
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </BeginStoryboard>
                                </EventTrigger>
                            </Button.Triggers>
                        </Button>
                    </Grid>
                </ControlTemplate>
            </MenuItem.Template>
        </MenuItem>
    </ContextMenu>

</ListView.Resources>
<ListView.ItemContainerStyle>
    <Style TargetType="{x:Type ListViewItem}" >
        <Setter Property="ContextMenu" Value="{StaticResource ItemContextMenu}" />
        <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
    </Style>
</ListView.ItemContainerStyle>