如何在 TabItems 上居中标题文本

Question

我正在尝试让我的 WPF TabItems 使其标题文本居中。但无论我在 ContentPresenter 及其包含的 Border 上设置了 Horizo​​ntalAlignment 和 Horizo​​ntalAlignment（居中或拉伸）的哪种组合，文本总是显示为左对齐，而不是居中。我也没有在 TabItems 上看到可以用来直接在选项卡项本身上设置它的属性（事实证明，TabItem 上的 Horizo​​ntalAlignment 做了完全不同的事情）。

我现在的代码是这样的：

<Grid TextElement.Foreground="White" TextElement.FontSize="17" TextElement.FontFamily="Times New Roman" HorizontalAlignment="Center" >
   <Border Name="TabBorder" BorderThickness="8 8 8 0"  CornerRadius="12 12 0 0"  
           Background="{StaticResource bandBrush}" HorizontalAlignment="Center" >
   <ContentPresenter HorizontalAlignment="Stretch" ContentSource="Header" Height="24" Width="100" />
   </Border>
 </Grid>

Answer 1

您可以将 ContentPresenter 放在 Label 中，将 Horizo​​ntalAlignment 属性设置为 Strecth，将 Horizo​​ntalContentAlignment 设置为 Center， 查看this:

<Grid x:Name="gridTabItem">
  <Border x:Name="Border" Margin="0,0,0,0" BorderBrush="{x:Null}" CornerRadius="7,7,0,0" BorderThickness="0" >
    <Label  x:Name="label" HorizontalAlignment="Stretch" HorizontalContentAlignment="Center">
      <ContentPresenter x:Name="ContentSite"
                      VerticalAlignment="Stretch"  
                 HorizontalAlignment="Center"
                 ContentSource="Header" Margin="10,2,10,2"
                 RecognizesAccessKey="True">
      </ContentPresenter>
    </Label>

  </Border>
  <Rectangle x:Name="rectangle" HorizontalAlignment="Left" Height="4" Margin="0,41, 0,0" Stroke="{x:Null}" VerticalAlignment="Top" Width="{Binding ActualWidth, ElementName=gridTabItem}" StrokeThickness="0" Fill="{x:Null}"/>
  <Rectangle x:Name="rectangle1" HorizontalAlignment="Left" Height="1" Margin="0,43,0,0" Stroke="{x:Null}" StrokeThickness="0" VerticalAlignment="Top" Width="{Binding ActualWidth, ElementName=gridTabItem}" Fill="#FFEEEEEE"/>
  <Rectangle x:Name="glow" HorizontalAlignment="Left" Height="41" Margin="0" Stroke="{x:Null}" StrokeThickness="0" VerticalAlignment="Top" Width="{Binding ActualWidth, ElementName=gridTabItem}" Fill="{x:Null}"/>
</Grid>

Answer 2

我知道这个问题有点老了，并且已经接受了答案，但我认为我的答案可以帮助某人。

我的问题是我需要均匀分布 TabItem 标题（每个 TabItem 标题具有相同的宽度）并且标题内的文本需要居中。所以这就是我实现这一目标的方式：

TabControl.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:local="clr-namespace:FMEA.Resources.Styles"
                xmlns:Converters="clr-namespace:FMEA.Converters"
                xmlns:Controls="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro">

<Style x:Key="Custom_TabItem" BasedOn="{StaticResource {x:Type TabItem}}" TargetType="{x:Type TabItem}">
    <Setter Property="Width">
        <Setter.Value>
            <MultiBinding>
                <MultiBinding.Converter>
                    <Converters:TabSizeConverter />
                </MultiBinding.Converter>
                <Binding RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType={x:Type TabControl}}" />
                <Binding RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType={x:Type TabControl}}" Path="ActualWidth" />
            </MultiBinding>
        </Setter.Value>
    </Setter>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TabItem}">
                <Grid x:Name="tabItem">
                    <Border x:Name="Border">
                        <ContentPresenter x:Name="content"
                                          VerticalAlignment="Center"  
                                          HorizontalAlignment="Center"
                                          ContentSource="Header" />
                    </Border>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter Property="Foreground" Value="Gray" />
                    </Trigger>
                    <Trigger Property="IsSelected" Value="False">
                        <Setter Property="Foreground" Value="LightGray" />
                    </Trigger>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter Property="Foreground" Value="Black" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="HeaderTemplate">
        <Setter.Value>
            <DataTemplate DataType="{x:Type TabItem}">
                <Border x:Name="border">
                    <ContentPresenter>
                        <ContentPresenter.Content>
                            <TextBlock Text="{TemplateBinding Content}"
                                       FontSize="22" HorizontalAlignment="Center" />
                        </ContentPresenter.Content>
                    </ContentPresenter>
                </Border>
            </DataTemplate>
        </Setter.Value>
    </Setter>
</Style>

</ResourceDictionary>

TabSizeConverter 在哪里：

class TabSizeConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        TabControl tabCtrl = values[0] as TabControl;
        double width = tabCtrl.ActualWidth / tabCtrl.Items.Count;
        return width <= 1 ? 0 : width - 1;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

使用示例：

<TabItem Header="MyHeader" Style="{StaticResource Custom_TabItem}">