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我有一段 XAML 代码，它为 StackPanel 中的一些按钮定义了一个模板：

<StackPanel x:Name="ThumbnailsStack">
   <StackPanel.Resources>
      <Style TargetType="Button">
         <Setter Property="Height" Value="120" />
         <Setter Property="Margin" Value="3" />
         <Setter Property="BorderThickness" Value="0" />
      </Style>
    </StackPanel.Resources>
 </StackPanel>

代码有效，堆栈内的所有按钮都采用定义的样式。现在我想为它们中的每一个附加一个 ContextMenu（来自 Toolkit 库）。我尝试了以下方法：

在 App.xaml 中

<Application.Resources>
    <toolkit:ContextMenu x:Key="ThumbBtnMenu">
        <toolkit:MenuItem Header="delete"></toolkit:MenuItem>
    </toolkit:ContextMenu>
</Application.Resources>

在前面的代码中，我添加了一个新标签：

<StackPanel x:Name="ThumbnailsStack">
   <StackPanel.Resources>
      <Style TargetType="Button">
         <Setter Property="Height" Value="120" />
         <Setter Property="Margin" Value="3" />
         <Setter Property="BorderThickness" Value="0" />
         <Setter Property="toolkit:ContextMenuService.ContextMenu" Value="{StaticResource ThumbBtnMenu}" />
      </Style>
    </StackPanel.Resources>
 </StackPanel>

现在，当页面加载时，它会引发一个System.Windows.Markup.XamlParseException: Failed to assign to property 'System.Windows.Setter.Value'

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1 回答 1

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问题是当您在资源中定义上下文菜单时，将只有一个 ContextMenu 实例（并且该实例将被添加到所有按钮），因此当它添加到可视树时会出现一些问题，因为一个项目只能有一个父母。

我认为您在样式级别定义上下文菜单的唯一方法实际上是在按钮的完整样式中定义它，例如：

<Style  TargetType="Button">
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="BorderBrush" Value="{StaticResource PhoneForegroundBrush}"/>
        <Setter Property="Foreground" Value="{StaticResource PhoneForegroundBrush}"/>
        <Setter Property="BorderThickness" Value="{StaticResource PhoneBorderThickness}"/>
        <Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilySemiBold}"/>
        <Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMedium}"/>
        <Setter Property="Padding" Value="10,5,10,6"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Grid Background="Transparent">
                        <toolkit:ContextMenuService.ContextMenu>
                            <toolkit:ContextMenu>
                                <toolkit:MenuItem Header="delete"></toolkit:MenuItem>
                            </toolkit:ContextMenu>
                        </toolkit:ContextMenuService.ContextMenu>
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="MouseOver"/>
                                <VisualState x:Name="Pressed">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentContainer">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneButtonBasePressedForegroundBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ButtonBackground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneAccentBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentContainer">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ButtonBackground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ButtonBackground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Border x:Name="ButtonBackground" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="0" Margin="{StaticResource PhoneTouchTargetOverhang}">
                            <ContentControl x:Name="ContentContainer" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Foreground="{TemplateBinding Foreground}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                        </Border>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
于 2013-09-19T22:07:17.560 回答