根据Windows Dev Center:

TextBlock。IsTextSelectionEnabled财产 [针对Windows 10上的UWP应用程序更新。]Windows 8。X篇文章，见 档案] 获取或设置一个值，该值指示是否启用文本选择 在TextBlock中，通过用户操作或调用 selection-related API。

我不确定你是否可以使一个TextBlock可选，但另一个选择是使用RichTextBox -它就像你建议的TextBox，但支持你想要的格式。

创建控件模板的TextBlock，并把一个文本框内readonly属性设置。 或者只是使用文本框，使其只读，然后你可以改变文本框。样式，使它看起来像TextBlock。

以下是对我有效的方法。我创建了一个类TextBlockEx，从TextBox派生，并设置为只读，文本包装在构造函数。

public class TextBlockEx : TextBox
{
    public TextBlockEx()
    {
        base.BorderThickness = new Thickness(0);
        IsReadOnly = true;
        TextWrapping = TextWrapping.Wrap;
        //Background = Brushes.Transparent; // Uncomment to get parent's background color
    }
}

只是在FlowDocumentScrollViewer中使用FlowDocument，将你的内联传递给元素。 你可以控制元素的样式，在我的例子中，我添加了一个小边框。

<FlowDocumentScrollViewer Grid.Row="2" Margin="5,3" BorderThickness="1" 
                          BorderBrush="{DynamicResource Element.Border}" 
                          VerticalScrollBarVisibility="Auto">
    <FlowDocument>
        <Paragraph>
            <Bold>Some bold text in the paragraph.</Bold>
            Some text that is not bold.
        </Paragraph>

        <List>
            <ListItem>
                <Paragraph>ListItem 1</Paragraph>
            </ListItem>
            <ListItem>
                <Paragraph>ListItem 2</Paragraph>
            </ListItem>
            <ListItem>
                <Paragraph>ListItem 3</Paragraph>
            </ListItem>
        </List>
    </FlowDocument>
</FlowDocumentScrollViewer>

为torvin的代码添加了Selection & SelectionChanged事件

public class SelectableTextBlock : TextBlock
{

    static readonly Type TextEditorType
    = Type.GetType("System.Windows.Documents.TextEditor, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");

    static readonly PropertyInfo IsReadOnlyProp
        = TextEditorType.GetProperty("IsReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);

    static readonly PropertyInfo TextViewProp
        = TextEditorType.GetProperty("TextView", BindingFlags.Instance | BindingFlags.NonPublic);

    static readonly MethodInfo RegisterMethod
        = TextEditorType.GetMethod("RegisterCommandHandlers",
        BindingFlags.Static | BindingFlags.NonPublic, null, new[] { typeof(Type), typeof(bool), typeof(bool), typeof(bool) }, null);

    static readonly Type TextContainerType
        = Type.GetType("System.Windows.Documents.ITextContainer, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");
    static readonly PropertyInfo TextContainerTextViewProp
        = TextContainerType.GetProperty("TextView");

    static readonly PropertyInfo TextContainerTextSelectionProp
        = TextContainerType.GetProperty("TextSelection");

    static readonly PropertyInfo TextContainerProp = typeof(TextBlock).GetProperty("TextContainer", BindingFlags.Instance | BindingFlags.NonPublic);

    static void RegisterCommandHandlers(Type controlType, bool acceptsRichContent, bool readOnly, bool registerEventListeners)
    {
        RegisterMethod.Invoke(null, new object[] { controlType, acceptsRichContent, readOnly, registerEventListeners });
    }

    static SelectableTextBlock()
    {
        FocusableProperty.OverrideMetadata(typeof(SelectableTextBlock), new FrameworkPropertyMetadata(true));
        RegisterCommandHandlers(typeof(SelectableTextBlock), true, true, true);

        // remove the focus rectangle around the control
        FocusVisualStyleProperty.OverrideMetadata(typeof(SelectableTextBlock), new FrameworkPropertyMetadata((object)null));
    }

    //private readonly TextEditorWrapper _editor;
    object? textContainer;
    object? editor;
    public TextSelection TextSelection { get; private set; }

    public SelectableTextBlock()
    {
        textContainer = TextContainerProp.GetValue(this);

        editor = Activator.CreateInstance(TextEditorType, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.CreateInstance,
            null, new[] { textContainer, this, false }, null);


        IsReadOnlyProp.SetValue(editor, true);
        TextViewProp.SetValue(editor, TextContainerTextViewProp.GetValue(textContainer));

        TextSelection = (TextSelection)TextContainerTextSelectionProp.GetValue(textContainer);
        TextSelection.Changed += (s, e) => OnSelectionChanged?.Invoke(this, e);
    }

    public event EventHandler OnSelectionChanged;
}