如何获取TabControl WPF的TabItem的表头宽度

就像一样简单

<StackPanel>
    <TabControl>
        <TabItem Header="Hello world" Name="Tab1"/>
        <TabItem Header="Hello" Name="Tab2"/>
        <TabItem Header="world" Name="Tab3"/>
    </TabControl>
    <TextBlock Text="{Binding ElementName=Tab1, Path=ActualWidth}"/>
    <TextBlock Text="{Binding ElementName=Tab2, Path=ActualWidth}"/>
    <TextBlock Text="{Binding ElementName=Tab3, Path=ActualWidth}"/>
</StackPanel>

刚刚做了以下AttachedProperty:

XAML用法

<TabControl question32926699:TabControlHeaderWidthWatcher.WatchHeadersWidth="true"
            question32926699:TabControlHeaderWidthWatcher.TotalHeadersWidth="{Binding TotalWidth, Mode=OneWayToSource}">
  <TabItem Header="Tab Item 1" />
  <TabItem Header="Tab Item 2" />
</TabControl>

附加属性

public class TabControlHeaderWidthWatcher
{
    private static TabControl m_tabControl;
    public static readonly DependencyProperty WatchHeadersWidthProperty = DependencyProperty.RegisterAttached(
        "WatchHeadersWidth", typeof (bool), typeof (TabControlHeaderWidthWatcher), new PropertyMetadata(default(bool), PropertyChangedCallback));
    public static void SetWatchHeadersWidth(DependencyObject element, bool value)
    {
        element.SetValue(WatchHeadersWidthProperty, value);
    }
    public static bool GetWatchHeadersWidth(DependencyObject element)
    {
        return (bool)element.GetValue(WatchHeadersWidthProperty);
    }
    public static readonly DependencyProperty TotalHeadersWidthProperty = DependencyProperty.RegisterAttached(
        "TotalHeadersWidth", typeof (double), typeof (TabControlHeaderWidthWatcher), new PropertyMetadata(default(double)));
    public static void SetTotalHeadersWidth(DependencyObject element, double value)
    {
        element.SetValue(TotalHeadersWidthProperty, value);
    }
    public static double GetTotalHeadersWidth(DependencyObject element)
    {
        return (double) element.GetValue(TotalHeadersWidthProperty);
    }
    private static void PropertyChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
    {
        m_tabControl = dependencyObject as TabControl;
        if (m_tabControl == null) return;
        ((INotifyCollectionChanged)m_tabControl.Items).CollectionChanged += CollectionChanged;
    }
    private static void CollectionChanged(object sender, EventArgs eventArgs)
    {
        foreach (var item in m_tabControl.Items)
        {
            var tabItem = item as TabItem;
            if (tabItem == null) continue;
            // Unsubscribe first in case it was there previously
            tabItem.SizeChanged -= TabItemOnSizeChanged;
            tabItem.SizeChanged += TabItemOnSizeChanged;
        }
    }
    private static void TabItemOnSizeChanged(object sender, SizeChangedEventArgs sizeChangedEventArgs)
    {
        var totalWidth = 0.0;
        foreach (var item in m_tabControl.Items)
        {
            var tabItem = item as TabItem;
            if (tabItem == null) continue;
            totalWidth += tabItem.ActualWidth;
        }
        // When more than one row of tabs, the width of the TabControl is used
        var actualWidth = totalWidth > m_tabControl.ActualWidth ? m_tabControl.ActualWidth : totalWidth;
        SetTotalHeadersWidth(m_tabControl, actualWidth);
    }
}

即使您使用TabControl的ItemsSource动态加载Tabs，此解决方案也会起作用。除非选项卡被包裹在多行中，否则TotalHeadersWidth将始终接收总标题宽度。在这种情况下，它将使用TabControl本身的ActualWidth，在您的情况下，这给出了我们想要的。