问TabControl在TabControl WPF中

EN

<Grid Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2">
   <TabControl ItemsSource="{Binding Tabs}">
      <TabControl.ItemTemplate>
         <!-- this is the header template-->
         <DataTemplate>
            <TextBlock Text="{Binding Header}" />
         </DataTemplate>
      </TabControl.ItemTemplate>
      <TabControl.ContentTemplate>
         <!-- this is the body of the TabItem template-->
         <DataTemplate>
            <TabControl ItemsSource="{Binding steps}">
               <TabControl.ItemTemplate>
                  <!-- this is the header template-->
                  <DataTemplate>
                     <TextBlock Text="{Binding Header}" />
                  </DataTemplate>
               </TabControl.ItemTemplate>
               <TabControl.ContentTemplate>
                  <!-- this is the body of the TabItem template-->
                  <DataTemplate>
                     <TextBlock Text="{Binding Content}" />
                  </DataTemplate>
               </TabControl.ContentTemplate>
            </TabControl>

            <TextBlock Text="{Binding Content}" />
         </DataTemplate>
      </TabControl.ContentTemplate>
   </TabControl>
</Grid>

public ObservableCollection<TabItem> Tabs { get; set; }

public AddElement()
{
   Steps step = new Steps();
   step.display = "1";

   Steps step2 = new Steps();
   step.display = "2";

   ObservableCollection<Steps> stepsList = new ObservableCollection<Steps>();
   stepsList.Add(step);
   stepsList.Add(step2);

   Tabs = new ObservableCollection<TabItem>();
   Tabs.Add(new TabItem { Header = "One", Content = "One's content", Steps = stepsList });
   Tabs.Add(new TabItem { Header = "Two", Content = "Two's content" });

}

public sealed class TabItem
{
   public string Header { get; set; }
   public string Content { get; set; }
   public ObservableCollection<Steps> Steps { get; set; }
}

public class Steps
{
   public string display { get; set; }
}