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;
}

有一个替代的解决方案，可能适用于这篇博客文章中提到的RichTextBox -它使用一个触发器来交换控件模板，当使用悬停在控件上时-应该有助于性能

我已经实现了SelectableTextBlock在我的开源控件库。你可以这样使用它:

<jc:SelectableTextBlock Text="Some text" />

添加到@torvin的答案，正如@Dave Huang在评论中提到的，如果你启用了texttrim ="CharacterEllipsis"，当你将鼠标悬停在省略号上时，应用程序会崩溃。

我尝试了关于使用TextBox的线程中提到的其他选项，但它似乎真的不是解决方案，因为它不显示“省省号”，也如果文本太长，以适合容器选择文本框的内容“滚动”内部这不是一个TextBlock行为。

我认为最好的解决方案是@torvin的答案，但当悬停在省略号上时，会出现令人讨厌的崩溃。

我知道这并不漂亮，但是在内部订阅/取消订阅未处理的异常和处理异常是我发现解决这个问题的唯一方法，如果有人有更好的解决方案，请分享:)

public class SelectableTextBlock : TextBlock
{
    static SelectableTextBlock()
    {
        FocusableProperty.OverrideMetadata(typeof(SelectableTextBlock), new FrameworkPropertyMetadata(true));
        TextEditorWrapper.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;

    public SelectableTextBlock()
    {
        _editor = TextEditorWrapper.CreateFor(this);

        this.Loaded += (sender, args) => {
            this.Dispatcher.UnhandledException -= Dispatcher_UnhandledException;
            this.Dispatcher.UnhandledException += Dispatcher_UnhandledException;
        };
        this.Unloaded += (sender, args) => {
            this.Dispatcher.UnhandledException -= Dispatcher_UnhandledException;
        };
    }

    private void Dispatcher_UnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
    {
        if (!string.IsNullOrEmpty(e?.Exception?.StackTrace))
        {
            if (e.Exception.StackTrace.Contains("System.Windows.Controls.TextBlock.GetTextPositionFromDistance"))
            {
                e.Handled = true;
            }
        }
    }
}

public MainPage()
{
    this.InitializeComponent();
    ...
    ...
    ...
    //Make Start result text copiable
    TextBlockStatusStart.IsTextSelectionEnabled = true;
}

使用带有这些设置的TextBox来使其只读，看起来像一个TextBlock控件。

<TextBox Background="Transparent"
         BorderThickness="0"
         Text="{Binding Text, Mode=OneWay}"
         IsReadOnly="True"
         TextWrapping="Wrap" />