在没有TemplateBinding的情况下，默认的ControlTemplates如何让你进行自定义？

Question

我是第一次接触WPF，所以我决定通过模板化TabControl来学习。我不得不在我的模板中使用{TemplateBinding BorderBrush}来识别<TabControl BorderBrush="Red">。这就是我所拥有的：

<ControlTemplate TargetType="TabControl">
    <Grid Name="grid" >
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <TabPanel Grid.Row="0" IsItemsHost="True"></TabPanel>
        <Border Grid.Row="1" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}"></Border>
    </Grid>
</ControlTemplate>

在查看TabControl Styles and Templates的默认模板时，我看到了以下内容：

<Border x:Name="Border"
        Grid.Row="1"
        BorderThickness="1"
        CornerRadius="2"
        KeyboardNavigation.TabNavigation="Local"
        KeyboardNavigation.DirectionalNavigation="Contained"
        KeyboardNavigation.TabIndex="2">
    <Border.Background>
        <LinearGradientBrush EndPoint="0.5,1"
                            StartPoint="0.5,0">
            <GradientStop Color="{DynamicResource ContentAreaColorLight}"
                            Offset="0" />
            <GradientStop Color="{DynamicResource ContentAreaColorDark}"
                            Offset="1" />
        </LinearGradientBrush>
    </Border.Background>
    <Border.BorderBrush>
       <SolidColorBrush Color="{DynamicResource BorderMediumColor}"/>
    </Border.BorderBrush>
    <ContentPresenter x:Name="PART_SelectedContentHost"
                        Margin="4"
                        ContentSource="SelectedContent" />
</Border>

它正在使用这里的资源：

<Color x:Key="BorderMediumColor">#FF888888</Color>

没有任何绑定，但它仍然可以识别BorderBrush。要理解这一点，我错过了哪些重要的知识？

Answer 1

事实证明，TabControl Styles and Templates中的模板不是默认的选项卡控件模板。我提取了Right click on TabControl in the Designer > Edit Template > Edit a Copy...的默认模板，得到的结果如下：

<SolidColorBrush x:Key="TabItem.Selected.Background" Color="#FFFFFF"/>
<SolidColorBrush x:Key="TabItem.Selected.Border" Color="#ACACAC"/>
<Style x:Key="TabControlStyle1" TargetType="{x:Type TabControl}">
    <Setter Property="Padding" Value="2"/>
    <Setter Property="HorizontalContentAlignment" Value="Center"/>
    <Setter Property="VerticalContentAlignment" Value="Center"/>
    <Setter Property="Background" Value="{StaticResource TabItem.Selected.Background}"/>
    <Setter Property="BorderBrush" Value="{StaticResource TabItem.Selected.Border}"/>
    <Setter Property="BorderThickness" Value="1"/>
    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TabControl}">
                <Grid x:Name="templateRoot" 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>
                    <TabPanel x:Name="headerPanel" Background="Transparent" Grid.Column="0" IsItemsHost="true" Margin="2,2,2,0" Grid.Row="0" KeyboardNavigation.TabIndex="1" Panel.ZIndex="1"/>
                    <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="TextElement.Foreground" TargetName="templateRoot" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

它包含：

<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>

看，TemplateBindings！我不再困惑了。