Wpf 我的RichTextBox附加属性有什么问题；附件“流动文件”；

您好，我尝试创建一个附加属性，以便能够将我的

FlowDocument

绑定到

RichTextBox

这是我的密码

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;

namespace Speiseplandienst.Tools
{
    public static class RichTextBoxHelper
    {
        public static FlowDocument GetDocument(DependencyObject obj)
        {
            return (FlowDocument)obj.GetValue(AttachFlowDocumentProperty);
        }

        public static void SetDocument(DependencyObject obj, FlowDocument value)
        {
            obj.SetValue(AttachFlowDocumentProperty, value);
        }

        public static readonly DependencyProperty AttachFlowDocumentProperty =
            DependencyProperty.RegisterAttached(
                "AttachFlowDocument",
                typeof(FlowDocument),
                typeof(RichTextBoxHelper),
                new FrameworkPropertyMetadata(
                    default(FlowDocument),
                    FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
                    OnPropertyChangedCallBack));

        private static void OnPropertyChangedCallBack(
            DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            var richTextBox = (RichTextBox)obj;

            // Parse the XAML to a document (or use XamlReader.Parse())

            try
            {
                // Set the document
                richTextBox.Document = GetDocument(richTextBox);
            }
            catch (Exception)
            {
                richTextBox.Document = new FlowDocument();
            }

            // When the document changes update the source
            richTextBox.TextChanged += (obj2, e2) =>
                {
                    RichTextBox richTextBox2 = obj2 as RichTextBox;
                    if (richTextBox2 != null)
                    {
                        SetDocument(obj, richTextBox2.Document);
                    }
                };
        }
    }
}

这里是Stacktrace：

   bei System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   bei System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)
   bei System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
   bei System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   bei Speiseplandienst.Views.MenuItemV.InitializeComponent() in c:\Users\MReimann\Desktop\...\...\...\...\MenuItemV.xaml:Zeile 1.
   bei Speiseplandienst.Views.MenuItemV..ctor() in c:\Users\MReimann\Desktop\...\...\...\...\MenuItemV.xaml.cs:Zeile 24.

这里是错误：

{"\"Binding\" kann nicht für die Eigenschaft \"SetDocument\" vom Typ \"RichTextBox\" festgelegt werden. \"Binding\" kann nur für eine \"DependencyProperty\" eines \"DependencyObject\" festgelegt werden."}

我知道这个错误意味着什么，但我不知道如何解决这个问题，因为我不知道我需要什么DependencyObject

---

如果有人能指出他期望的对象，那就太好了。附加属性

X

的静态getter和setter方法的名称必须是

GetX

和

SetX

。因此，如果您有一个附加属性

AttachFlowDocument

，它们必须如下所示：

public static FlowDocument GetAttachFlowDocument(DependencyObject obj)
{
    return (FlowDocument)obj.GetValue(AttachFlowDocumentProperty);
}

public static void SetAttachFlowDocumentDocument(
    DependencyObject obj, FlowDocument value)
{
    obj.SetValue(AttachFlowDocumentProperty, value);
}