Question

我对ContextMenu有一个小问题。

<Window.Resources>
    <Style x:Key="ButtonWithContextMenuStyle" TargetType="Button">
        <Setter Property="Background" Value="#cbeb00" />
        <Setter Property="Foreground" Value="#505050" />
        <Setter Property="FontSize" Value="12" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Border CornerRadius="4" Background="{TemplateBinding Background}"
                            BorderThickness="0">
                        <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" Margin="{TemplateBinding Padding}" />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Background" Value="#aaaaaa"/>
                            <Setter Property="Foreground" Value="#dcff00"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="ContextMenu">
            <Setter.Value>
                <ContextMenu>
                    <MenuItem Command="{Binding EditUserCommand}" Header="{DynamicResource EditUserContextMenuMW}"/>
                    <MenuItem Command="{Binding OpenHistoryCommand}" Header="{DynamicResource ConversationHistoryContextMenuMW}"/>
                    <MenuItem Command="{Binding OpenHistoryCommand}" Header="{DynamicResource BuyCreditContextMenuMW}"/>
                    <Separator />
                    <MenuItem Command="{Binding LogoutCommand}" Header="{DynamicResource LogoutContextMenuMW}"/>
                </ContextMenu>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <EventTrigger RoutedEvent="Click" >
                <EventTrigger.Actions>
                    <BeginStoryboard>
                        <Storyboard>
                            <BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="ContextMenu.IsOpen">
                                <DiscreteBooleanKeyFrame KeyTime="0:0:0" Value="True"/>
                            </BooleanAnimationUsingKeyFrames>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger.Actions>
            </EventTrigger>
        </Style.Triggers>
    </Style>
</Window.Resources>

当我单击鼠标右键时，一切正常。 ContextMenu打开，我可以在MenuItem上调用Command。

当我点击鼠标左键时，我想看到相同的行为。但是，只有ContextMenu打开，我无法调用Command。

有人能告诉我我做错了什么吗？

Answer 1

<Window x:Class="ContextMenuMouseDownStack.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<StackPanel Margin="10">
    <StackPanel.Resources>
        <Style TargetType="Button">
            <Style.Triggers>
                <EventTrigger RoutedEvent="Click">
                    <EventTrigger.Actions>
                        <BeginStoryboard>
                            <Storyboard>
                                <BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="ContextMenu.IsOpen">
                                    <DiscreteBooleanKeyFrame KeyTime="0:0:2" Value="True"/>
                                </BooleanAnimationUsingKeyFrames>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger.Actions>
                </EventTrigger>
            </Style.Triggers>
        </Style>
    </StackPanel.Resources>
    <Button Content="Click!" VerticalAlignment="Center" HorizontalAlignment="Center">
        <Button.ContextMenu>
            <ContextMenu>
                <MenuItem Header="Menu item 1" Click="MenuItem_Click"/>
                <MenuItem Header="Menu item 2" />
                <Separator />
                <MenuItem Header="Menu item 3" />
            </ContextMenu>
        </Button.ContextMenu>
    </Button>
</StackPanel>

在这个类似于你的例子中，Click事件可以完成工作。实际上，我没有那里的Command，只是处理程序背后的简单代码。它以两种方式到达它，鼠标右键或左键单击。只是为了测试，你可以尝试一个简单的处理程序吗？

更新1：

对我来说，它也适用于两种方式：

<EventTrigger RoutedEvent="PreviewMouseDown">

更新2

你的故事板似乎毁了这些东西：

我用这样的Popup改变了这个：

    <Popup x:Name="btnMenuPopup" Placement="Mouse" StaysOpen="False">
        <Border BorderBrush="Black" BorderThickness="2" CornerRadius="2">
            <Menu>
                <MenuItem Header="Menu item 1" Command="{Binding EditCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}"/>
                <MenuItem Header="Menu item 2" />
                <Separator />
                <MenuItem Header="Menu item 3" />
                <Menu.ItemsPanel>
                    <ItemsPanelTemplate>
                        <VirtualizingStackPanel Orientation="Vertical"/>
                    </ItemsPanelTemplate>
                </Menu.ItemsPanel>
            </Menu>
        </Border>
    </Popup>

为了快速，我在按钮上添加了一个点击事件，这将打开弹出窗口。

 private void Button_Click(object sender, RoutedEventArgs e)
 {
   btnMenuPopup.IsOpen = true;
 }

现在应该可以了。

这是弹出窗口的命令：

  Command="{Binding CommandShowPopup}" CommandParameter="{Binding ElementName=btnMenuPopup}"

命令实施：

public class CommandShowPopup : ICommand
{
    public bool CanExecute(object parameter)
    {
        return true;
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        (parameter as Popup).IsOpen = true;
    }
}

Answer 2

您需要使用MouseRightButtonDown路由事件。

<EventTrigger RoutedEvent="MouseRightButtonDown">

在左键单击下使用ContextMenu的WPF按钮

2 个答案: