RichTextBox中的绑定不起作用

Question

我有一个绑定到Run＆＃39; Text属性。我绑定到单个类属性。以下是代码和示例：

xaml代码：

 <Grid>
    <RichTextBox>
        <RichTextBox.Document>
            <FlowDocument>
                <Paragraph >
                    <Run Text="{Binding TestText,Mode=TwoWay}"></Run>
                </Paragraph>
            </FlowDocument>
        </RichTextBox.Document>
    </RichTextBox>
</Grid>

代码背后的代码：

public MainWindow()
    {
        InitializeComponent();
        this.DataContext = this;

        this.PropertyChanged += MainWindow_PropertyChanged;
    }


    private string text = "TestText";

    public string TestText
    {
        get { return text; }
        set
        {
            if (text == value) return;
            text = value;
            OnPropertyChanged("TestText");
        }
    }

    private void MainWindow_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        Console.WriteLine(TestText);
    }


    #region NotifyPropertyChanged

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    #endregion

当我输入1,2,3,4,5时 我得到了＆＃34; 5＆＃34;而不是＆＃34; 5Te4st3Te2xt1＆＃34;