如何关注WPF TabControl新添加的TabItem？

我面临一个问题，我需要能够真正集中精力TabItem选项卡中的TabControl就像我会按TAB钥匙。我知道我可以使用SendKeys.SendWait("{TAB}");为了实现这一目标，但我更喜欢更强大的解决方案。

选项卡项绑定到ItemSource of an ObservableCollection。该集合包含稍后绑定到选项卡项标题、图标、内容等的视图模型列表。该集合在运行时填充和清空，我没有静态集合。

我制作了一个示例项目来说明该问题（请参阅下面的代码）。

Current behavior after I added a tab item to the collection looks like this:

按左侧的“添加选项卡”按钮后，一个新选项卡将添加到ObservableCollection然后反映在选项卡控件中的新选项卡项中。

我尝试将新选项卡的重点放在：

• Set the SelectedItem of the TabControl添加新项目后（参见下面的代码）
• Keyboard.Focus((UIElement)sender)在选项卡项加载事件中（参见下面的代码）
• 通过设置FocusManager.FocusedElement="{Binding ElementName=tabHeader}"在 XAML 中（参见下面的代码）

这些尝试似乎都不起作用。

期望的行为新添加的选项卡项目实际上会获得焦点（就像我会按TABkey) 看起来像这样：

为了创建这个图像，我按下了TAB添加新选项卡项目后。

我找不到任何可行的解决方案here https://stackoverflow.com/questions/1227132/how-can-i-make-a-specific-tabitem-gain-focus-on-a-tabcontrol-without-click-event or here https://social.msdn.microsoft.com/Forums/vstudio/en-US/d32ba76f-9c58-4a70-9845-deaf1771fce2/setting-keyboard-focus-after-switch-to-new-tabitem-in-a-tabcontrol?forum=wpf并且Microsoft 有关 Focus 的文档 https://learn.microsoft.com/en-us/dotnet/desktop/wpf/advanced/focus-overview?view=netframeworkdesktop-4.8没有提供足够的光线。

任何提示表示赞赏。

要重现上面的屏幕截图，请使用我的示例项目：

主窗口.xaml

<Window x:Class="WpfAppTabControl.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfAppTabControl"
        mc:Ignorable="d"
        d:DataContext="{d:DesignInstance local:MainViewViewModel}"
        Title="MainWindow" Height="450" Width="800">
    <Grid>

    <Grid.RowDefinitions>
      <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
      <ColumnDefinition Width="350"/>
      <ColumnDefinition Width="12"/>
      <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>

    <Button Grid.Column="0" Grid.Row="2" Margin="50,50,50,50" Command="{Binding AddTabCommand}">Add Tab</Button>

    <GridSplitter Grid.Column="1" Grid.Row="2" ResizeDirection="Columns" ResizeBehavior="PreviousAndNext" HorizontalAlignment="Stretch"/>

    <TabControl Grid.Column="2"
                Grid.Row="2"
                ItemsSource="{Binding ItemsToDisplay}"
                SelectedItem="{Binding ActiveTabItem}"
                SelectionChanged="OnSelectionChanged"
                HorizontalContentAlignment="Stretch"
                VerticalContentAlignment="Stretch"
                FocusManager.FocusedElement="{Binding ElementName=tabHeader}"
                FocusManager.IsFocusScope="True">
      <TabControl.ItemContainerStyle>
        <Style TargetType="TabItem">
          <EventSetter Event="Loaded" Handler="OnTabItemLoaded"/>
          <Setter Property="IsSelected" Value="True"/>
          <Setter Property="Focusable" Value="True"/>
          <Setter Property="HeaderTemplate">
            <Setter.Value>
              <DataTemplate>
                <DockPanel x:Name="tabHeader" Margin="-5,-1,-5,0" Focusable="True">
                  <Button x:Name="closeButton"
                          Width="16"
                          Height="16"
                          Margin="20, 10, 10, 10"
                          Command="{Binding CloseTabCommand}"
                          CommandParameter="{Binding Title}"
                          BorderBrush="Transparent"
                          DockPanel.Dock="Right"
                          BorderThickness="0">
                    <Image x:Name="tabIcon" Source="/close.png" Height="16" Margin="0,0,0,0" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                  </Button>
                  <TextBlock Margin="5, 10, 10, 10" VerticalAlignment="Center" Text="{Binding Title}"/>
                </DockPanel>
              </DataTemplate>
            </Setter.Value>
          </Setter>
          <Setter Property="Content" Value="{Binding Content}" />
        </Style>
      </TabControl.ItemContainerStyle>
    </TabControl>

  </Grid>
</Window>

MainWindow.xaml.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace WpfAppTabControl
{
   public partial class MainWindow : Window
   {
      public MainWindow()
      {
         InitializeComponent();
         DataContext = new MainViewViewModel();
      }

      private void OnSelectionChanged(object sender, SelectionChangedEventArgs e)
      {
         var viewModel = (MainViewViewModel)DataContext;
         viewModel.NotifySelectedItemChanged(e.AddedItems);
      }

      private void OnTabItemLoaded(object sender, RoutedEventArgs e)
      {
         Keyboard.Focus((UIElement)sender);
      }
   }
}

ItemViewModel.cs

using Prism.Mvvm;
using System;
using System.Windows.Input;

namespace WpfAppTabControl
{
   public class ItemViewModel : BindableBase, IDisposable
   {
      private string title;
      private string content;

      public ItemViewModel(ICommand closeTabCommand)
      {
         CloseTabCommand = closeTabCommand ?? throw new ArgumentNullException(nameof(closeTabCommand));
      }

      public string Title
      {
         get => title;

         set
         {
            if (title != value)
            {
               title = value;
               RaisePropertyChanged(title);
            }
         }
      }
      public string Content
      {
         get => content;

         set
         {
            if (content != value)
            {
               content = value;
               RaisePropertyChanged(content);
            }
         }
      }

      public ICommand CloseTabCommand
      {
         get;
         private set;
      }

      public void Dispose()
      {
         // disposing stuff
      }
   }
}

MainViewViewModel.cs

using Prism.Commands;
using Prism.Mvvm;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Windows.Input;

namespace WpfAppTabControl
{
   public class MainViewViewModel : BindableBase
   {
      private readonly ObservableCollection<ItemViewModel> itemsToDisplay;
      private ItemViewModel activeTabItem;

      public MainViewViewModel()
      {
         itemsToDisplay = new ObservableCollection<ItemViewModel>();
         AddTabCommand = new DelegateCommand(AddTab);
      }

      public IEnumerable<ItemViewModel> ItemsToDisplay => itemsToDisplay;

      public ICommand AddTabCommand
      {
         get;
         private set;
      }

      public ItemViewModel ActiveTabItem
      {
         get => activeTabItem;
         set
         {
            if (activeTabItem != value)
            {
               activeTabItem = value;
               RaisePropertyChanged();
            }
         }
      }

      private void AddTab()
      {
         var tabCountString = (itemsToDisplay.Count + 1).ToString();
         var itemViewModel1 = new ItemViewModel(new DelegateCommand<string>(title => { CloseTab(title); }))
         {
            Title = "NewTab" + tabCountString,
            Content = "Content of " + "NewTab" + tabCountString,
         };

         itemsToDisplay.Add(itemViewModel1);
         ActiveTabItem = itemViewModel1;
      }

      private void CloseTab(string title)
      {
         if (string.IsNullOrEmpty(title))
         {
            return;
         }

         var tabToClose = itemsToDisplay.FirstOrDefault(viewModel => viewModel.Title == title);
         if (tabToClose != null)
         {
            itemsToDisplay.Remove(tabToClose);
         }
      }

      public void NotifySelectedItemChanged(IList addedItems)
      {
         if (addedItems.Count > 0)
         {
            // stuff to do
         }
      }
   }
}

有同样的问题。将新的 tabitem 添加到 tabcontrol：示例TabItem newtabitem = new TabItem然后使用newtabitem.Focus()。这会将焦点移至添加的选项卡。