Question

我有一个绑定到富文本框，为此我创建了一个帮助器。我绑定到单个类属性。以下是代码和示例：

这是我创建的助手：

public class RichTextBoxHelper
{

    /// <summary>
    /// Text Attached Dependency Property
    /// </summary>
    public static readonly DependencyProperty TextProperty =
        DependencyProperty.RegisterAttached("Text", typeof(string), typeof(RichTextBoxHelper),
            new FrameworkPropertyMetadata((string)null,
                FrameworkPropertyMetadataOptions.BindsTwoWayByDefault |
                FrameworkPropertyMetadataOptions.Journal, 
                new PropertyChangedCallback(OnTextChanged),
                new CoerceValueCallback(CoerceText),
                true,
                UpdateSourceTrigger.PropertyChanged));


    /// <summary>
    /// Gets the Text property.
    /// </summary>
    public static string GetText(DependencyObject d)
    {
        return (string)d.GetValue(TextProperty);
    }

    /// <summary>
    /// Sets the Text property.
    /// </summary>
    public static void SetText(DependencyObject d, string value)
    {
        d.SetValue(TextProperty, value);
    }

    /// <summary>
    /// Returns the Text from a FlowDocument
    /// </summary>
    /// <param name="document">The document to get the text from</param>
    /// <returns>Returns a string with the text of the flow document</returns>
    public static string GetText(FlowDocument document)
    {
        return new TextRange(document.ContentStart, document.ContentEnd).Text;
    }

    /// <summary>
    /// Handles changes to the Text property.
    /// </summary>
    private static void OnTextChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        RichTextBox textBox = (RichTextBox)d;
        if (e.NewValue != null)
        {
            textBox.Document.Blocks.Clear();
            textBox.Document.Blocks.Add(new Paragraph(new Run(e.NewValue.ToString())));
        }
    }

    private static object CoerceText(DependencyObject d, object value) 
    {
        return value ?? "";
    }

XAML中的代码是：

<RichTextBox Name="txtView" 
                                                     AcceptsReturn="False" 
                                                     Grid.Column="2" 
                                                     Grid.Row="5" 
                                                     BorderThickness="0" 
                                                     Margin="2,5,5,2" 
                                                     HorizontalAlignment="Stretch" 
                                                     HorizontalScrollBarVisibility="Auto" 
                                                     VerticalScrollBarVisibility="Auto"
                                                     local:RichTextBoxHelper.Text="{Binding SelectedItem.ItemData.Description}">

我的View模型中的Selected项目是：

public DataDetail SelectedItem
    {
        get
        {
            return this.selectedItem;
        }
        set
        {
            this.selectedItem = value;
            base.RaisePropertyChanged("SelectedItem");
        }
    }

DataDetail类的结构和嵌套属性如下：

public class DataDetail
{
    public ItemData ItemData { get; set; }
    // Other properies (other class objects 
}

public class ItemData
{
    public string Name { get; set; }
    public string Description { get; set; }
    // Other properties (string and int, float)
}

问题是Richbox中的数据是从这个属性中读取的，但当我尝试更改Richtextbox中的任何内容时（在UI中），它不会进入该属性。当我将Name属性绑定到文本框并且通过在XAML中指定它时可以工作（读取和更新）

<TextBox Text="{Binding SelectedItem.ItemData.Name}"></TextBox>

Richtext框中有什么问题？

感谢任何帮助。

吉里贾

Answer 1

属性如何知道它发生了变化？没有描述它应该与RichTextBox中段落的内容相对应。您需要观察RichTextBox内容及其Text属性的所有更改，并手动change the current value查看附加的Text属性。

富文本框中的双向绑定不起作用

1 个答案: