WPF上下文菜单样式未应用于代码添加的MenuItem问题求助

当前你定义的conte样式仅针对ContextMenu容器本身，未为其中的MenuItem定义统一样式规则。XAML中静态声明的MenuItem可能继承了全局默认样式，而代码动态创建的MenuItem会使用系统默认样式，导致样式不统一。下面提供三种解决方案：

方案一：定义全局MenuItem样式 #

在ResourceDictionary中添加无x:Key的MenuItem样式，所有MenuItem（包括动态创建的）会自动应用该样式：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <!-- 保留原有ContextMenu样式conte -->
    <Style TargetType="{x:Type ContextMenu}" x:Key="conte">
        <!-- 原有代码不变 -->
    </Style>

    <!-- 全局MenuItem样式 -->
    <Style TargetType="{x:Type MenuItem}">
        <Setter Property="Background" Value="{DynamicResource PrimaryDark}"/>
        <Setter Property="Foreground" Value="{DynamicResource Secendery}"/>
        <Setter Property="Padding" Value="8,4"/>
        <!-- 自定义MenuItem模板，可按需调整 -->
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type MenuItem}">
                    <Border x:Name="ItemBorder" Background="{TemplateBinding Background}" CornerRadius="3">
                        <ContentPresenter Content="{TemplateBinding Header}" Margin="{TemplateBinding Padding}" VerticalAlignment="Center"/>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter TargetName="ItemBorder" Property="Background" Value="#44FFFFFF"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter Property="Foreground" Value="#88FFFFFF"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

方案二：在ContextMenu样式中设置ItemContainerStyle #

修改现有的conte样式，添加ItemContainerStyle属性，仅对该ContextMenu内的MenuItem生效：

<Style TargetType="{x:Type ContextMenu}" x:Key="conte">
    <Setter Property="Background" Value="{DynamicResource PrimaryDark}" />
    <Setter Property="Foreground" Value="{DynamicResource Secendery}" />
    <Setter Property="SnapsToDevicePixels" Value="True" />
    <Setter Property="OverridesDefaultStyle" Value="True" />
    <Setter Property="HasDropShadow" Value="True" />

    <!-- 添加ItemContainerStyle，作用于菜单内所有MenuItem -->
    <Setter Property="ItemContainerStyle">
        <Setter.Value>
            <Style TargetType="{x:Type MenuItem}">
                <Setter Property="Background" Value="{DynamicResource PrimaryDark}"/>
                <Setter Property="Foreground" Value="{DynamicResource Secendery}"/>
                <Setter Property="Padding" Value="8,4"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type MenuItem}">
                            <Border x:Name="ItemBorder" Background="{TemplateBinding Background}" CornerRadius="3">
                                <ContentPresenter Content="{TemplateBinding Header}" Margin="{TemplateBinding Padding}" VerticalAlignment="Center"/>
                            </Border>
                            <ControlTemplate.Triggers>
                                <Trigger Property="IsMouseOver" Value="True">
                                    <Setter TargetName="ItemBorder" Property="Background" Value="#44FFFFFF"/>
                                </Trigger>
                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </Setter.Value>
    </Setter>

    <!-- 保留原有ContextTemplate -->
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ContextMenu}">
                <Border x:Name="Border" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding Foreground}" BorderThickness="0.5" CornerRadius="5">
                    <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle" />
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="HasDropShadow" Value="true">
                        <Setter TargetName="Border" Property="Padding" Value="0,3,0,3" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

方案三：动态创建时手动指定样式 #

如果需要为不同动态子项设置个性化样式，可在代码中手动赋值样式：

1. 先在ResourceDictionary中定义带x:Key的MenuItem样式：

<Style TargetType="{x:Type MenuItem}" x:Key="CustomMenuItemStyle">
    <Setter Property="Background" Value="{DynamicResource PrimaryDark}"/>
    <Setter Property="Foreground" Value="{DynamicResource Secendery}"/>
    <!-- 其他样式设置 -->
</Style>

2. 在代码中动态创建并赋值：

// 从资源中获取样式
var customStyle = (Style)FindResource("CustomMenuItemStyle");

// 创建动态子项
var dynamicSubItem = new MenuItem
{
    Header = "动态子菜单",
    Style = customStyle
};

// 添加到ConnectMenuItem
ConnectMenuItem.Items.Add(dynamicSubItem);

内容的提问来源于stack exchange，提问作者VindE