您需要覆盖 TabControl 的整个模板。
幸运的是,使用 Visual Studio 可以轻松提取模板副本(在“文档大纲”窗口中的 TabControl 元素上右键单击 -> 编辑模板 -> 编辑副本)。
在默认 TabControl 模板 HeaderPanel 中定义如下:
<TabPanel x:Name="HeaderPanel" Grid.Column="0" IsItemsHost="true" Margin="2,2,2,0" Grid.Row="0" KeyboardNavigation.TabIndex="1" Panel.ZIndex="1"/>
主要思想是通过设置 IsItemsHost="true" 将 TabControl.Items 绑定到完全另一种控件类型,而不是绑定到 Panel 控件。
例如,要绑定到具有开箱即用的溢出按钮功能的工具栏:
<ToolBar x:Name="HeaderPanel" ItemsSource="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Items}"/>
以下是 TabControl 模板的完整示例,其中 ToolBar 作为标题面板:
<TabControl>
<TabControl.Template>
<ControlTemplate TargetType="{x:Type TabControl}">
<Grid ClipToBounds="true" SnapsToDevicePixels="true" KeyboardNavigation.TabNavigation="Local">
<Grid.ColumnDefinitions>
<ColumnDefinition x:Name="ColumnDefinition0"/>
<ColumnDefinition x:Name="ColumnDefinition1" Width="0"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition x:Name="RowDefinition0" Height="Auto"/>
<RowDefinition x:Name="RowDefinition1" Height="*"/>
</Grid.RowDefinitions>
<!--this will do the trick!!!-->
<ToolBar x:Name="HeaderPanel" ItemsSource="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Items}"/>
<Border x:Name="ContentPanel" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.Column="0" KeyboardNavigation.DirectionalNavigation="Contained" Grid.Row="1" KeyboardNavigation.TabIndex="2" KeyboardNavigation.TabNavigation="Local">
<ContentPresenter x:Name="PART_SelectedContentHost" ContentSource="SelectedContent" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="TabStripPlacement" Value="Bottom">
<Setter Property="Grid.Row" TargetName="HeaderPanel" Value="1"/>
<Setter Property="Grid.Row" TargetName="ContentPanel" Value="0"/>
<Setter Property="Height" TargetName="RowDefinition0" Value="*"/>
<Setter Property="Height" TargetName="RowDefinition1" Value="Auto"/>
<Setter Property="Margin" TargetName="HeaderPanel" Value="2,0,2,2"/>
</Trigger>
<Trigger Property="TabStripPlacement" Value="Left">
<Setter Property="Grid.Row" TargetName="HeaderPanel" Value="0"/>
<Setter Property="Grid.Row" TargetName="ContentPanel" Value="0"/>
<Setter Property="Grid.Column" TargetName="HeaderPanel" Value="0"/>
<Setter Property="Grid.Column" TargetName="ContentPanel" Value="1"/>
<Setter Property="Width" TargetName="ColumnDefinition0" Value="Auto"/>
<Setter Property="Width" TargetName="ColumnDefinition1" Value="*"/>
<Setter Property="Height" TargetName="RowDefinition0" Value="*"/>
<Setter Property="Height" TargetName="RowDefinition1" Value="0"/>
<Setter Property="Margin" TargetName="HeaderPanel" Value="2,2,0,2"/>
</Trigger>
<Trigger Property="TabStripPlacement" Value="Right">
<Setter Property="Grid.Row" TargetName="HeaderPanel" Value="0"/>
<Setter Property="Grid.Row" TargetName="ContentPanel" Value="0"/>
<Setter Property="Grid.Column" TargetName="HeaderPanel" Value="1"/>
<Setter Property="Grid.Column" TargetName="ContentPanel" Value="0"/>
<Setter Property="Width" TargetName="ColumnDefinition0" Value="*"/>
<Setter Property="Width" TargetName="ColumnDefinition1" Value="Auto"/>
<Setter Property="Height" TargetName="RowDefinition0" Value="*"/>
<Setter Property="Height" TargetName="RowDefinition1" Value="0"/>
<Setter Property="Margin" TargetName="HeaderPanel" Value="0,2,2,2"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</TabControl.Template>
</TabControl>