我想修改 TopLevelHeader 以不显示任何边框和悬停效果。为此，我使用以下MSDN示例覆盖了默认的MenuItem样式：
http://msdn.microsoft.com/en-us/library/ms747082(v=vs.90).aspx
我的问题是，使用此样式，子项目将以透明背景显示。我也尝试使用aero.normalcolor.xaml样式，但问题仍然存在，子项具有透明背景。
相关部分：
<Style x:Key="SimpleMenuItemBasic" TargetType="{x:Type MenuItem}">
<Style.Triggers>
<Trigger Property="Role" Value="TopLevelHeader">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type MenuItem}">
<Border Name="Border" >
<Grid>
<ContentPresenter ContentSource="Header" RecognizesAccessKey="True" />
<Popup Name="Popup"
Placement="Bottom"
IsOpen="{TemplateBinding IsSubmenuOpen}"
AllowsTransparency="True"
Focusable="False"
PopupAnimation="Fade">
<Border Name="SubmenuBorder" SnapsToDevicePixels="True"
Background="{DynamicResource WindowBackgroundBrush}"
BorderBrush="{DynamicResource SolidBorderBrush}"
BorderThickness="1">
<ItemsPresenter KeyboardNavigation.DirectionalNavigation="Cycle"
KeyboardNavigation.TabNavigation="Cycle"
Margin="0,0,0,1"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
</Popup>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSuspendingPopupAnimation" Value="true">
<Setter TargetName="Popup" Property="PopupAnimation" Value="None"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="true">
<Setter TargetName="Border" Property="Background" Value="{DynamicResource NormalBrush}"/>
<Setter TargetName="Border" Property="BorderBrush" Value="Transparent"/>
</Trigger>
<Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="True">
<Setter TargetName="SubmenuBorder" Property="CornerRadius" Value="0,0,4,4"/>
<Setter TargetName="SubmenuBorder" Property="Padding" Value="0,0,0,3"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Foreground" Value="{DynamicResource DisabledForegroundBrush}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Grid.IsSharedSizeScope" Value="true"/>
</Trigger>
</Style.Triggers>
</Style>
用法示例：
<Menu>
<MenuItem Header="menuItem1" Style="{StaticResource SimpleMenuItemBasic}">
<MenuItem Header="subitem1" />
<MenuItem Header="subitem2" />
</MenuItem>
</Menu>
答案 0 :(得分：2)
第1步 - 为Visual Studio打开混合（以前的表达式混合）
Visual Studio的Blend是样式工具。它很棒，每个造型的人都应该更频繁地使用它。
使用Visual Studio 2012和2013，您应该使用MSDN订阅进行混合。
第2步 - 在Blend中打开您的解决方案。
第3步 - 右键单击MenuItem，然后选择“编辑模板”编辑副本。
这将创建所使用的默认样式的副本。它创建了整个样式的副本。这将是很多Xaml。我通常在一个单独的ResourceDictionary文件中创建它，但是对于这个例子，我将把它放在MainWindow资源中。
步骤4 - 注释影响Top MenuItem的默认样式中的突出显示内容。
第5步 - 只保留你改变的内容。
我们只需在一个控件模板中注释掉一个触发器。所以让我们删除除ControlTemplate之外的所有额外内容。
注意：我留下了我注释掉的东西，所以你可以看到它。
现在，当您突出显示顶部MenuItem时，没有任何反应。但是当您右键单击并弹出子菜单时，一切都与正常情况相同。
这是由此产生的Xaml。希望这会对你有所帮助。
MainWindow.xaml
<Window x:Class="StackOverflowMenuTransparent.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">
<Grid>
<Grid.Resources>
<!--<SolidColorBrush x:Key="MenuItem.Highlight.Background" Color="#3D26A0DA"/>
<SolidColorBrush x:Key="MenuItem.Highlight.Border" Color="#FF26A0DA"/>-->
<SolidColorBrush x:Key="Menu.Disabled.Foreground" Color="#FF707070"/>
<SolidColorBrush x:Key="Menu.Static.Border" Color="#FF999999"/>
<SolidColorBrush x:Key="Menu.Static.Background" Color="#FFF0F0F0"/>
<SolidColorBrush x:Key="Menu.Static.Separator" Color="#FFD7D7D7"/>
<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>
<ControlTemplate x:Key="NoHoverMenuItemTemplate" TargetType="{x:Type MenuItem}">
<Border x:Name="templateRoot" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" 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}" Fill="{TemplateBinding Foreground}" FlowDirection="LeftToRight" Margin="3" Visibility="Collapsed" VerticalAlignment="Center"/>
<ContentPresenter Grid.Column="1" ContentSource="Header" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Focusable="false" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" Placement="Bottom" PlacementTarget="{Binding ElementName=templateRoot}">
<Border x:Name="SubMenuBorder" BorderBrush="{StaticResource Menu.Static.Border}" BorderThickness="1" Background="{StaticResource Menu.Static.Background}" Padding="2">
<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>
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Menu Grid.Row="0">
<MenuItem Header="_File" Template="{DynamicResource NoHoverMenuItemTemplate}" >
<MenuItem Header="_Open" />
<MenuItem Header="_Save" />
</MenuItem>
<MenuItem Header="_Help" Template="{DynamicResource NoHoverMenuItemTemplate}" >
<MenuItem Header="_About" />
</MenuItem>
</Menu>
<TextBox Grid.Row="1" AcceptsReturn="True">
<TextBox.ContextMenu>
<ContextMenu>
</ContextMenu>
</TextBox.ContextMenu>
</TextBox>
</Grid>
</Window>