如何删除菜单项的白色边框？
How can I remove the Menu Item white border?
我说的就是这个。
我试过摆弄模板，但无法弄清楚。
这是我的 XAML 到目前为止。
<Border BorderThickness="0" HorizontalAlignment="Left" Height="30" Margin="3,30,0,0" Background="#242424" VerticalAlignment="Top" Width="660">
<Menu HorizontalAlignment="Left" Height="27" VerticalAlignment="Top" FontFamily="Segoe UI" Width="645" Background="#FF242424" Margin="10,3,0,0">
<MenuItem Header="File" FontSize="14" Padding="2" Foreground="White">
<MenuItem Header="Save" BorderThickness="0" Background="#2d2d2d" Foreground="White"/>
<MenuItem Header="Open" BorderThickness="0" Background="#2d2d2d" Foreground="White"/>
</MenuItem>
</Menu>
</Border>
边框在 Menu 控件的 ControlTemplate 中声明。请参阅 official documentation 应用自定义样式。
为了去除边框，您必须编辑包含 Border.
的控件模板
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}" BorderThickness="0" BorderBrush="{StaticResource Menu.Static.Border}" Padding="2">
您注意到的边框实际上是由hard-coded BorderThickness和Padding造成的。
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}">
如果您删除默认的顶级header模板和子菜单header模板 MenuItem 的样式（参见下面的代码），可见边框消失，如下所示。
您可以提取 MenuItem using Blend or Visual Studio 的默认样式和模板。然后你只需要调整上面的行。这是为样式和模板改编的 XAML 代码：
<SolidColorBrush x:Key="Menu.Static.Background" Color="#FFF0F0F0"/>
<SolidColorBrush x:Key="Menu.Static.Border" Color="#FF999999"/>
<SolidColorBrush x:Key="Menu.Static.Foreground" Color="#FF212121"/>
<SolidColorBrush x:Key="Menu.Static.Separator" Color="#FFD7D7D7"/>
<SolidColorBrush x:Key="Menu.Disabled.Foreground" Color="#FF707070"/>
<SolidColorBrush x:Key="MenuItem.Selected.Background" Color="#3D26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Selected.Border" Color="#FF26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Background" Color="#3D26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Border" Color="#FF26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Disabled.Background" Color="#0A000000"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Disabled.Border" Color="#21000000"/>
<MenuScrollingVisibilityConverter x:Key="MenuScrollingVisibilityConverter"/>
<Geometry x:Key="DownArrow">M 0,0 L 3.5,4 L 7,0 Z</Geometry>
<Geometry x:Key="UpArrow">M 0,4 L 3.5,0 L 7,4 Z</Geometry>
<Geometry x:Key="RightArrow">M 0,0 L 4,3.5 L 0,7 Z</Geometry>
<Geometry x:Key="Checkmark">F1 M 10.0,1.2 L 4.7,9.1 L 4.5,9.1 L 0,5.2 L 1.3,3.5 L 4.3,6.1L 8.3,0 L 10.0,1.2 Z</Geometry>
<Style x:Key="MenuScrollButton" BasedOn="{x:Null}" TargetType="{x:Type RepeatButton}">
<Setter Property="ClickMode" Value="Hover"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Border x:Name="templateRoot" Background="Transparent" BorderThickness="1" BorderBrush="Transparent" SnapsToDevicePixels="true">
<ContentPresenter HorizontalAlignment="Center" Margin="6" VerticalAlignment="Center"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="{ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}" BasedOn="{x:Null}" TargetType="{x:Type ScrollViewer}">
<Setter Property="HorizontalScrollBarVisibility" Value="Hidden"/>
<Setter Property="VerticalScrollBarVisibility" Value="Auto"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ScrollViewer}">
<Grid SnapsToDevicePixels="true">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Border Grid.Column="0" Grid.Row="1">
<ScrollContentPresenter CanContentScroll="{TemplateBinding CanContentScroll}" Margin="{TemplateBinding Padding}"/>
</Border>
<RepeatButton Command="{x:Static ScrollBar.LineUpCommand}" CommandTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Grid.Column="0" Focusable="false" Grid.Row="0" Style="{StaticResource MenuScrollButton}">
<RepeatButton.Visibility>
<MultiBinding Converter="{StaticResource MenuScrollingVisibilityConverter}" ConverterParameter="0" FallbackValue="Visibility.Collapsed">
<Binding Path="ComputedVerticalScrollBarVisibility" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="VerticalOffset" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ExtentHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ViewportHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
</MultiBinding>
</RepeatButton.Visibility>
<Path Data="{StaticResource UpArrow}" Fill="{StaticResource Menu.Static.Foreground}"/>
</RepeatButton>
<RepeatButton Command="{x:Static ScrollBar.LineDownCommand}" CommandTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Grid.Column="0" Focusable="false" Grid.Row="2" Style="{StaticResource MenuScrollButton}">
<RepeatButton.Visibility>
<MultiBinding Converter="{StaticResource MenuScrollingVisibilityConverter}" ConverterParameter="100" FallbackValue="Visibility.Collapsed">
<Binding Path="ComputedVerticalScrollBarVisibility" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="VerticalOffset" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ExtentHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ViewportHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
</MultiBinding>
</RepeatButton.Visibility>
<Path Data="{StaticResource DownArrow}" Fill="{StaticResource Menu.Static.Foreground}"/>
</RepeatButton>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=TopLevelItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" SnapsToDevicePixels="true">
<Grid VerticalAlignment="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Path x:Name="GlyphPanel" Data="{StaticResource Checkmark}" FlowDirection="LeftToRight" Fill="{StaticResource Menu.Static.Foreground}" Margin="3" VerticalAlignment="Center" Visibility="Collapsed"/>
<ContentPresenter ContentSource="Header" Grid.Column="1" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="GlyphPanel" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsHighlighted" Value="True"/>
<Condition Property="IsEnabled" Value="False"/>
</MultiTrigger.Conditions>
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Border}"/>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=TopLevelHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" SnapsToDevicePixels="true">
<Grid VerticalAlignment="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Path x:Name="GlyphPanel" Data="{StaticResource Checkmark}" FlowDirection="LeftToRight" Fill="{TemplateBinding Foreground}" Margin="3" VerticalAlignment="Center" Visibility="Collapsed"/>
<ContentPresenter ContentSource="Header" Grid.Column="1" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Focusable="false" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Bottom" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" PlacementTarget="{Binding ElementName=templateRoot}">
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}">
<ScrollViewer x:Name="SubMenuScrollViewer" Style="{DynamicResource {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}}">
<Grid RenderOptions.ClearTypeHint="Enabled">
<Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=SubMenuBorder}" Height="{Binding ActualHeight, ElementName=SubMenuBorder}" Width="{Binding ActualWidth, ElementName=SubMenuBorder}"/>
</Canvas>
<Rectangle Fill="{StaticResource Menu.Static.Separator}" HorizontalAlignment="Left" Margin="29,2,0,2" Width="1"/>
<ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Cycle" Grid.IsSharedSizeScope="true" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.TabNavigation="Cycle"/>
</Grid>
</ScrollViewer>
</Border>
</Popup>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSuspendingPopupAnimation" Value="true">
<Setter Property="PopupAnimation" TargetName="PART_Popup" Value="None"/>
</Trigger>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="GlyphPanel" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<Trigger Property="ScrollViewer.CanContentScroll" SourceName="SubMenuScrollViewer" Value="false">
<Setter Property="Canvas.Top" TargetName="OpaqueRect" Value="{Binding VerticalOffset, ElementName=SubMenuScrollViewer}"/>
<Setter Property="Canvas.Left" TargetName="OpaqueRect" Value="{Binding HorizontalOffset, ElementName=SubMenuScrollViewer}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=SubmenuItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Height="22" SnapsToDevicePixels="true">
<Grid Margin="-1">
<Grid.ColumnDefinitions>
<ColumnDefinition MinWidth="22" SharedSizeGroup="MenuItemIconColumnGroup" Width="Auto"/>
<ColumnDefinition Width="13"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="30"/>
<ColumnDefinition SharedSizeGroup="MenuItemIGTColumnGroup" Width="Auto"/>
<ColumnDefinition Width="20"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Border x:Name="GlyphPanel" Background="{StaticResource MenuItem.Selected.Background}" BorderThickness="1" BorderBrush="{StaticResource MenuItem.Selected.Border}" ClipToBounds="False" HorizontalAlignment="Center" Height="22" Margin="-1,0,0,0" VerticalAlignment="Center" Visibility="Hidden" Width="22">
<Path x:Name="Glyph" Data="{StaticResource Checkmark}" FlowDirection="LeftToRight" Fill="{StaticResource Menu.Static.Foreground}" Height="11" Width="10"/>
</Border>
<ContentPresenter x:Name="menuHeaderContainer" ContentSource="Header" Grid.Column="2" HorizontalAlignment="Left" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center"/>
<TextBlock x:Name="menuGestureText" Grid.Column="4" Margin="{TemplateBinding Padding}" Opacity="0.7" Text="{TemplateBinding InputGestureText}" VerticalAlignment="Center"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="Glyph" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsHighlighted" Value="True"/>
<Condition Property="IsEnabled" Value="False"/>
</MultiTrigger.Conditions>
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Border}"/>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=SubmenuHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Height="22" SnapsToDevicePixels="true">
<Grid Margin="-1">
<Grid.ColumnDefinitions>
<ColumnDefinition MinWidth="22" SharedSizeGroup="MenuItemIconColumnGroup" Width="Auto"/>
<ColumnDefinition Width="13"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="30"/>
<ColumnDefinition SharedSizeGroup="MenuItemIGTColumnGroup" Width="Auto"/>
<ColumnDefinition Width="20"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Border x:Name="GlyphPanel" Background="{StaticResource MenuItem.Highlight.Background}" BorderThickness="1" BorderBrush="{StaticResource MenuItem.Highlight.Border}" Height="22" Margin="-1,0,0,0" VerticalAlignment="Center" Visibility="Hidden" Width="22">
<Path x:Name="Glyph" Data="{DynamicResource Checkmark}" FlowDirection="LeftToRight" Fill="{StaticResource Menu.Static.Foreground}" Height="11" Width="9"/>
</Border>
<ContentPresenter ContentSource="Header" Grid.Column="2" HorizontalAlignment="Left" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center"/>
<TextBlock Grid.Column="4" Margin="{TemplateBinding Padding}" Opacity="0.7" Text="{TemplateBinding InputGestureText}" VerticalAlignment="Center"/>
<Path x:Name="RightArrow" Grid.Column="5" Data="{StaticResource RightArrow}" Fill="{StaticResource Menu.Static.Foreground}" HorizontalAlignment="Left" Margin="10,0,0,0" VerticalAlignment="Center"/>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Focusable="false" HorizontalOffset="-2" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Right" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" VerticalOffset="-3">
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}">
<ScrollViewer x:Name="SubMenuScrollViewer" Style="{DynamicResource {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}}">
<Grid RenderOptions.ClearTypeHint="Enabled">
<Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=SubMenuBorder}" Height="{Binding ActualHeight, ElementName=SubMenuBorder}" Width="{Binding ActualWidth, ElementName=SubMenuBorder}"/>
</Canvas>
<Rectangle Fill="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" HorizontalAlignment="Left" Margin="29,2,0,2" Width="1"/>
<ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Cycle" Grid.IsSharedSizeScope="true" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.TabNavigation="Cycle"/>
</Grid>
</ScrollViewer>
</Border>
</Popup>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSuspendingPopupAnimation" Value="true">
<Setter Property="PopupAnimation" TargetName="PART_Popup" Value="None"/>
</Trigger>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="Transparent"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="Glyph" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="RightArrow" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<Trigger Property="ScrollViewer.CanContentScroll" SourceName="SubMenuScrollViewer" Value="false">
<Setter Property="Canvas.Top" TargetName="OpaqueRect" Value="{Binding VerticalOffset, ElementName=SubMenuScrollViewer}"/>
<Setter Property="Canvas.Left" TargetName="OpaqueRect" Value="{Binding HorizontalOffset, ElementName=SubMenuScrollViewer}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<Style TargetType="{x:Type MenuItem}">
<Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="ScrollViewer.PanningMode" Value="Both"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=SubmenuItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
<Style.Triggers>
<Trigger Property="Role" Value="TopLevelHeader">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="Foreground" Value="{StaticResource Menu.Static.Foreground}"/>
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=TopLevelHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
<Setter Property="Padding" Value="6,0"/>
</Trigger>MenuItem
<Trigger Property="Role" Value="TopLevelItem">
<Setter Property="Background" Value="{StaticResource Menu.Static.Background}"/>
<Setter Property="BorderBrush" Value="{StaticResource Menu.Static.Border}"/>
<Setter Property="Foreground" Value="{StaticResource Menu.Static.Foreground}"/>
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=TopLevelItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
<Setter Property="Padding" Value="6,0"/>
</Trigger>
<Trigger Property="Role" Value="SubmenuHeader">
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=SubmenuHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
</Trigger>
</Style.Triggers>
</Style>
将代码复制到范围内的资源字典中。 MenuItem 的样式是隐式的，因此它会自动应用于范围内的所有 MenuItems。如果您只想有选择地应用此样式，请添加一个 x:Key 使其显式化并通过 StaticResource 或 DynamicResource 标记扩展引用它。
当然，您可以使用 documentation 中关于 MenuItem 样式和模板的指导来滚动您自己的自定义菜单项样式，这些样式和模板具有所需的状态和部分，但这是一项复杂的任务，并且容易出错，因此更容易复制和调整默认样式。
我说的就是这个。
我试过摆弄模板，但无法弄清楚。 这是我的 XAML 到目前为止。
<Border BorderThickness="0" HorizontalAlignment="Left" Height="30" Margin="3,30,0,0" Background="#242424" VerticalAlignment="Top" Width="660">
<Menu HorizontalAlignment="Left" Height="27" VerticalAlignment="Top" FontFamily="Segoe UI" Width="645" Background="#FF242424" Margin="10,3,0,0">
<MenuItem Header="File" FontSize="14" Padding="2" Foreground="White">
<MenuItem Header="Save" BorderThickness="0" Background="#2d2d2d" Foreground="White"/>
<MenuItem Header="Open" BorderThickness="0" Background="#2d2d2d" Foreground="White"/>
</MenuItem>
</Menu>
</Border>
边框在 Menu 控件的 ControlTemplate 中声明。请参阅 official documentation 应用自定义样式。
为了去除边框，您必须编辑包含 Border.
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}" BorderThickness="0" BorderBrush="{StaticResource Menu.Static.Border}" Padding="2">
您注意到的边框实际上是由hard-coded BorderThickness和Padding造成的。
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}">
如果您删除默认的顶级header模板和子菜单header模板 MenuItem 的样式（参见下面的代码），可见边框消失，如下所示。
您可以提取 MenuItem using Blend or Visual Studio 的默认样式和模板。然后你只需要调整上面的行。这是为样式和模板改编的 XAML 代码：
<SolidColorBrush x:Key="Menu.Static.Background" Color="#FFF0F0F0"/>
<SolidColorBrush x:Key="Menu.Static.Border" Color="#FF999999"/>
<SolidColorBrush x:Key="Menu.Static.Foreground" Color="#FF212121"/>
<SolidColorBrush x:Key="Menu.Static.Separator" Color="#FFD7D7D7"/>
<SolidColorBrush x:Key="Menu.Disabled.Foreground" Color="#FF707070"/>
<SolidColorBrush x:Key="MenuItem.Selected.Background" Color="#3D26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Selected.Border" Color="#FF26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Background" Color="#3D26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Border" Color="#FF26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Disabled.Background" Color="#0A000000"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Disabled.Border" Color="#21000000"/>
<MenuScrollingVisibilityConverter x:Key="MenuScrollingVisibilityConverter"/>
<Geometry x:Key="DownArrow">M 0,0 L 3.5,4 L 7,0 Z</Geometry>
<Geometry x:Key="UpArrow">M 0,4 L 3.5,0 L 7,4 Z</Geometry>
<Geometry x:Key="RightArrow">M 0,0 L 4,3.5 L 0,7 Z</Geometry>
<Geometry x:Key="Checkmark">F1 M 10.0,1.2 L 4.7,9.1 L 4.5,9.1 L 0,5.2 L 1.3,3.5 L 4.3,6.1L 8.3,0 L 10.0,1.2 Z</Geometry>
<Style x:Key="MenuScrollButton" BasedOn="{x:Null}" TargetType="{x:Type RepeatButton}">
<Setter Property="ClickMode" Value="Hover"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Border x:Name="templateRoot" Background="Transparent" BorderThickness="1" BorderBrush="Transparent" SnapsToDevicePixels="true">
<ContentPresenter HorizontalAlignment="Center" Margin="6" VerticalAlignment="Center"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="{ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}" BasedOn="{x:Null}" TargetType="{x:Type ScrollViewer}">
<Setter Property="HorizontalScrollBarVisibility" Value="Hidden"/>
<Setter Property="VerticalScrollBarVisibility" Value="Auto"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ScrollViewer}">
<Grid SnapsToDevicePixels="true">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Border Grid.Column="0" Grid.Row="1">
<ScrollContentPresenter CanContentScroll="{TemplateBinding CanContentScroll}" Margin="{TemplateBinding Padding}"/>
</Border>
<RepeatButton Command="{x:Static ScrollBar.LineUpCommand}" CommandTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Grid.Column="0" Focusable="false" Grid.Row="0" Style="{StaticResource MenuScrollButton}">
<RepeatButton.Visibility>
<MultiBinding Converter="{StaticResource MenuScrollingVisibilityConverter}" ConverterParameter="0" FallbackValue="Visibility.Collapsed">
<Binding Path="ComputedVerticalScrollBarVisibility" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="VerticalOffset" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ExtentHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ViewportHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
</MultiBinding>
</RepeatButton.Visibility>
<Path Data="{StaticResource UpArrow}" Fill="{StaticResource Menu.Static.Foreground}"/>
</RepeatButton>
<RepeatButton Command="{x:Static ScrollBar.LineDownCommand}" CommandTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Grid.Column="0" Focusable="false" Grid.Row="2" Style="{StaticResource MenuScrollButton}">
<RepeatButton.Visibility>
<MultiBinding Converter="{StaticResource MenuScrollingVisibilityConverter}" ConverterParameter="100" FallbackValue="Visibility.Collapsed">
<Binding Path="ComputedVerticalScrollBarVisibility" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="VerticalOffset" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ExtentHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
<Binding Path="ViewportHeight" RelativeSource="{RelativeSource TemplatedParent}"/>
</MultiBinding>
</RepeatButton.Visibility>
<Path Data="{StaticResource DownArrow}" Fill="{StaticResource Menu.Static.Foreground}"/>
</RepeatButton>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=TopLevelItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" SnapsToDevicePixels="true">
<Grid VerticalAlignment="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Path x:Name="GlyphPanel" Data="{StaticResource Checkmark}" FlowDirection="LeftToRight" Fill="{StaticResource Menu.Static.Foreground}" Margin="3" VerticalAlignment="Center" Visibility="Collapsed"/>
<ContentPresenter ContentSource="Header" Grid.Column="1" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="GlyphPanel" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsHighlighted" Value="True"/>
<Condition Property="IsEnabled" Value="False"/>
</MultiTrigger.Conditions>
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Border}"/>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=TopLevelHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" SnapsToDevicePixels="true">
<Grid VerticalAlignment="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Path x:Name="GlyphPanel" Data="{StaticResource Checkmark}" FlowDirection="LeftToRight" Fill="{TemplateBinding Foreground}" Margin="3" VerticalAlignment="Center" Visibility="Collapsed"/>
<ContentPresenter ContentSource="Header" Grid.Column="1" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Focusable="false" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Bottom" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" PlacementTarget="{Binding ElementName=templateRoot}">
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}">
<ScrollViewer x:Name="SubMenuScrollViewer" Style="{DynamicResource {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}}">
<Grid RenderOptions.ClearTypeHint="Enabled">
<Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=SubMenuBorder}" Height="{Binding ActualHeight, ElementName=SubMenuBorder}" Width="{Binding ActualWidth, ElementName=SubMenuBorder}"/>
</Canvas>
<Rectangle Fill="{StaticResource Menu.Static.Separator}" HorizontalAlignment="Left" Margin="29,2,0,2" Width="1"/>
<ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Cycle" Grid.IsSharedSizeScope="true" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.TabNavigation="Cycle"/>
</Grid>
</ScrollViewer>
</Border>
</Popup>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSuspendingPopupAnimation" Value="true">
<Setter Property="PopupAnimation" TargetName="PART_Popup" Value="None"/>
</Trigger>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="GlyphPanel" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<Trigger Property="ScrollViewer.CanContentScroll" SourceName="SubMenuScrollViewer" Value="false">
<Setter Property="Canvas.Top" TargetName="OpaqueRect" Value="{Binding VerticalOffset, ElementName=SubMenuScrollViewer}"/>
<Setter Property="Canvas.Left" TargetName="OpaqueRect" Value="{Binding HorizontalOffset, ElementName=SubMenuScrollViewer}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=SubmenuItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Height="22" SnapsToDevicePixels="true">
<Grid Margin="-1">
<Grid.ColumnDefinitions>
<ColumnDefinition MinWidth="22" SharedSizeGroup="MenuItemIconColumnGroup" Width="Auto"/>
<ColumnDefinition Width="13"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="30"/>
<ColumnDefinition SharedSizeGroup="MenuItemIGTColumnGroup" Width="Auto"/>
<ColumnDefinition Width="20"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Border x:Name="GlyphPanel" Background="{StaticResource MenuItem.Selected.Background}" BorderThickness="1" BorderBrush="{StaticResource MenuItem.Selected.Border}" ClipToBounds="False" HorizontalAlignment="Center" Height="22" Margin="-1,0,0,0" VerticalAlignment="Center" Visibility="Hidden" Width="22">
<Path x:Name="Glyph" Data="{StaticResource Checkmark}" FlowDirection="LeftToRight" Fill="{StaticResource Menu.Static.Foreground}" Height="11" Width="10"/>
</Border>
<ContentPresenter x:Name="menuHeaderContainer" ContentSource="Header" Grid.Column="2" HorizontalAlignment="Left" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center"/>
<TextBlock x:Name="menuGestureText" Grid.Column="4" Margin="{TemplateBinding Padding}" Opacity="0.7" Text="{TemplateBinding InputGestureText}" VerticalAlignment="Center"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="Glyph" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsHighlighted" Value="True"/>
<Condition Property="IsEnabled" Value="False"/>
</MultiTrigger.Conditions>
<Setter Property="Background" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Disabled.Border}"/>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ControlTemplate x:Key="{ComponentResourceKey ResourceId=SubmenuHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Height="22" SnapsToDevicePixels="true">
<Grid Margin="-1">
<Grid.ColumnDefinitions>
<ColumnDefinition MinWidth="22" SharedSizeGroup="MenuItemIconColumnGroup" Width="Auto"/>
<ColumnDefinition Width="13"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="30"/>
<ColumnDefinition SharedSizeGroup="MenuItemIGTColumnGroup" Width="Auto"/>
<ColumnDefinition Width="20"/>
</Grid.ColumnDefinitions>
<ContentPresenter x:Name="Icon" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>
<Border x:Name="GlyphPanel" Background="{StaticResource MenuItem.Highlight.Background}" BorderThickness="1" BorderBrush="{StaticResource MenuItem.Highlight.Border}" Height="22" Margin="-1,0,0,0" VerticalAlignment="Center" Visibility="Hidden" Width="22">
<Path x:Name="Glyph" Data="{DynamicResource Checkmark}" FlowDirection="LeftToRight" Fill="{StaticResource Menu.Static.Foreground}" Height="11" Width="9"/>
</Border>
<ContentPresenter ContentSource="Header" Grid.Column="2" HorizontalAlignment="Left" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center"/>
<TextBlock Grid.Column="4" Margin="{TemplateBinding Padding}" Opacity="0.7" Text="{TemplateBinding InputGestureText}" VerticalAlignment="Center"/>
<Path x:Name="RightArrow" Grid.Column="5" Data="{StaticResource RightArrow}" Fill="{StaticResource Menu.Static.Foreground}" HorizontalAlignment="Left" Margin="10,0,0,0" VerticalAlignment="Center"/>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Focusable="false" HorizontalOffset="-2" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Right" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" VerticalOffset="-3">
<Border x:Name="SubMenuBorder" Background="{StaticResource Menu.Static.Background}">
<ScrollViewer x:Name="SubMenuScrollViewer" Style="{DynamicResource {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}}">
<Grid RenderOptions.ClearTypeHint="Enabled">
<Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=SubMenuBorder}" Height="{Binding ActualHeight, ElementName=SubMenuBorder}" Width="{Binding ActualWidth, ElementName=SubMenuBorder}"/>
</Canvas>
<Rectangle Fill="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" HorizontalAlignment="Left" Margin="29,2,0,2" Width="1"/>
<ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Cycle" Grid.IsSharedSizeScope="true" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.TabNavigation="Cycle"/>
</Grid>
</ScrollViewer>
</Border>
</Popup>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSuspendingPopupAnimation" Value="true">
<Setter Property="PopupAnimation" TargetName="PART_Popup" Value="None"/>
</Trigger>
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Visibility" TargetName="GlyphPanel" Value="Visible"/>
<Setter Property="Visibility" TargetName="Icon" Value="Collapsed"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="True">
<Setter Property="Background" TargetName="templateRoot" Value="Transparent"/>
<Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource MenuItem.Highlight.Border}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="TextElement.Foreground" TargetName="templateRoot" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="Glyph" Value="{StaticResource Menu.Disabled.Foreground}"/>
<Setter Property="Fill" TargetName="RightArrow" Value="{StaticResource Menu.Disabled.Foreground}"/>
</Trigger>
<Trigger Property="ScrollViewer.CanContentScroll" SourceName="SubMenuScrollViewer" Value="false">
<Setter Property="Canvas.Top" TargetName="OpaqueRect" Value="{Binding VerticalOffset, ElementName=SubMenuScrollViewer}"/>
<Setter Property="Canvas.Left" TargetName="OpaqueRect" Value="{Binding HorizontalOffset, ElementName=SubMenuScrollViewer}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<Style TargetType="{x:Type MenuItem}">
<Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="ScrollViewer.PanningMode" Value="Both"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=SubmenuItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
<Style.Triggers>
<Trigger Property="Role" Value="TopLevelHeader">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="Foreground" Value="{StaticResource Menu.Static.Foreground}"/>
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=TopLevelHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
<Setter Property="Padding" Value="6,0"/>
</Trigger>MenuItem
<Trigger Property="Role" Value="TopLevelItem">
<Setter Property="Background" Value="{StaticResource Menu.Static.Background}"/>
<Setter Property="BorderBrush" Value="{StaticResource Menu.Static.Border}"/>
<Setter Property="Foreground" Value="{StaticResource Menu.Static.Foreground}"/>
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=TopLevelItemTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
<Setter Property="Padding" Value="6,0"/>
</Trigger>
<Trigger Property="Role" Value="SubmenuHeader">
<Setter Property="Template" Value="{DynamicResource {ComponentResourceKey ResourceId=SubmenuHeaderTemplateKey, TypeInTargetAssembly={x:Type MenuItem}}}"/>
</Trigger>
</Style.Triggers>
</Style>
将代码复制到范围内的资源字典中。 MenuItem 的样式是隐式的，因此它会自动应用于范围内的所有 MenuItems。如果您只想有选择地应用此样式，请添加一个 x:Key 使其显式化并通过 StaticResource 或 DynamicResource 标记扩展引用它。
当然，您可以使用 documentation 中关于 MenuItem 样式和模板的指导来滚动您自己的自定义菜单项样式，这些样式和模板具有所需的状态和部分，但这是一项复杂的任务，并且容易出错，因此更容易复制和调整默认样式。