这是我的代码

自定义类

public class CustomClass : Control
{
    public TabControl TabControl1
    {
        get { return (TabControl)GetValue(TabControl1Property); }
        set { SetValue(TabControl1Property, value); }
    }

    public static readonly DependencyProperty TabControl1Property =
        DependencyProperty.Register("TabControl1", typeof(TabControl), typeof(CustomClass), new PropertyMetadata(null));

}

字符串

MainWindow.xaml

<Window x:Class="SampleWithoutSFControl.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:SampleWithoutSFControl"
        mc:Ignorable="d"
 
        Title="MainWindow" Height="450" Width="800">

    <local:CustomClass >
        <local:CustomClass.TabControl1>
            <TabControl>
                <TabItem x:Name="tabItem" Header="Item1" DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:MainWindow}}}">
                    <Label Content="{Binding Name1}"/>
                </TabItem>
            </TabControl>
        </local:CustomClass.TabControl1>
    </local:CustomClass>
</Window>

型

MainWindow.xaml.cs

public partial class MainWindow : Window
    {
        
        public MainWindow()
        {
            InitializeComponent();
           // tabItem.DataContext = this;  //but uncomment this solves the problem!
        }
        public string Name1 => "Sync";
    }

型
运行代码，尝试打开“TabControl可见性”复选框。请注意，“Sync”不会出现在TabItem中，尽管它应该出现，因为TabItem的DataContext被设置为MainWindow控件。
为了解决这个问题，我需要通过取消注解这行代码来设置DataContext

// tabItem.DataContext = this;

型
但这两者不是完全等同的吗？为什么会这样？