如何获取 TabControl WPF 的 TabItem 的宽度 header

Question

我需要做的是在超出范围并隐藏 TabControl 之前停止 GridSplitter。因此，我想到的想法是将 TabItems 的所有 Header 的 ActualWidths 的总和绑定到 TabControl 的 MinWidth 或保留 TabControl 的 Crid Cell。但问题是到目前为止我无法访问 TabItem 的 Header 的宽度。我发现的一种解决方案是在 Tabitem.Header 中放置一个 TextBlock，声明其宽度并用 x:Name 命名。但是以这种方式使用宽度并不能给出 Header 的总宽度，包括边距和填充等，因此它甚至无法接近准确度。

更新

好的，这是代码。请注意，我已经实施了其中一种解决方案，但如果动态加载选项卡，它不会控制 MinWidth。

<Grid Background="#FFD6DBE9" Height="614" Width="1109">
        <Grid.RowDefinitions>
            <RowDefinition Height="89"/>
            <RowDefinition Height="Auto" MinHeight="{Binding ActualHeight, ElementName=gridNotificationsHeader}"/>
            <RowDefinition Height="494*"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="400*" MinWidth="{Binding MinWidth, ElementName=tabDataEntities}"/>
            <ColumnDefinition Width="Auto"/>
            <ColumnDefinition Width="144*">
                <ColumnDefinition.MinWidth>
                    <MultiBinding Converter="{StaticResource StringSumtoIntConvert}">
                        <Binding ElementName="cdLblNotificationsHeader" Path="MinWidth"/>
                        <Binding ElementName="cdBtnNotificationsClose" Path="ActualWidth"/>
                    </MultiBinding>
                </ColumnDefinition.MinWidth>
            </ColumnDefinition>

        </Grid.ColumnDefinitions>
        <GridSplitter x:Name="gridSplitter" Grid.Column="1" HorizontalAlignment="Center" Grid.Row="1" Width="2" Grid.RowSpan="2"/>
        <Grid x:Name="gridNotificationsHeader" Grid.Column="2" Background="#FF657695" 
          Grid.Row="1">
            <Grid.ColumnDefinitions>
                <ColumnDefinition x:Name="cdLblNotificationsHeader" MinWidth="{Binding Width, ElementName=lblNotificationsHeader}"/>
                <ColumnDefinition x:Name="cdBtnNotificationsClose" Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Label x:Name="lblNotificationsHeader" Content="Notifications" VerticalAlignment="Top" 
               FontSize="14.667" Height="30" Foreground="#FFEBF0EE" HorizontalAlignment="Left" Width="92"/>
            <Button x:Name="btnNotificationsClose" Content="X" 
                Margin="0,5,8,0" VerticalAlignment="Top" Width="20" FontFamily="Verdana" HorizontalAlignment="Right" Background="Transparent" FontSize="13.333" Foreground="Black" Grid.Column="1"/>
        </Grid>
        <TabControl x:Name="tabDataEntities" Margin="0,0,5,10" Grid.Row="1" Grid.RowSpan="2" FontSize="12" Grid.ColumnSpan="1" MinWidth="{Binding ElementName=TabItemOne, Path=ActualWidth}">
            <TabItem x:Name="TabItemOne">
                <TabItem.Header>Tab Item</TabItem.Header>
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
        </TabControl>
    </Grid>

Answer 1

就这么简单

<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>

Answer 2

刚刚在做以下事情时玩得很开心 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>

附上属性

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 动态加载选项卡，此解决方案也能正常工作。 TotalHeadersWidth 将始终接收总 headers 宽度，除非选项卡被包裹在多行中。在这种情况下，它将使用 TabControl 本身的 ActualWidth，在您的情况下，它给出了我们想要的。

如何获取 TabControl WPF 的 TabItem 的宽度 header

How to get Width of header of a TabItem of TabControl WPF

c#

wpf

tabitem

actualwidth