Question

没有为附加属性调用我的OnPropertyChangedCallback。我希望在运行应用程序时默认调用此方法。

我的代码编译。
我在“输出”窗口中没有错误。

有什么建议吗？

附属财产：

namespace FileModifier.Behaviors
{
    public class AttachedProperties : DependencyObject
    {
        public static readonly DependencyProperty TextProperty =
            DependencyProperty.Register("Text", typeof(string), typeof(AttachedProperties), new PropertyMetadata(null, OnPropertyChangedCallback));

        public static void SetText(DependencyObject d, string value)
        {
            d.SetValue(TextProperty, value);
        }

        public static string GetText(DependencyObject d)
        {
            return d.GetValue(TextProperty) as string;
        }

        private static void OnPropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var richEditBox = d as RichTextBox;
            var textRange = new TextRange(richEditBox.Document.ContentStart, richEditBox.Document.ContentEnd);
            throw new NotImplementedException();
        }
    }
}

XAML：

<RichTextBox x:Name="FileContentControl" IsReadOnly="True"
   behaviors:AttachedProperties.Text="{Binding ElementName=FileListView, Path=SelectedItem, 
    Converter={StaticResource FilePathToContentConverter}}"
   VerticalAlignment="Center" Padding="10" />

。。

<ListView x:Name="FileListView" ItemsSource="{Binding FilePaths}" Grid.Column="2" Grid.Row="0"
          SelectedItem="{Binding SelectedFilePath}"
          VerticalAlignment="Center"
          Margin="5">

    <ListView.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Converter={StaticResource TextTruncationConverter}}" />
        </DataTemplate>
    </ListView.ItemTemplate>

    <ListView.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="Foreground" Value="Blue" />
            <Setter Property="Padding" Value="5" />
        </Style>
    </ListView.ItemContainerStyle>
</ListView>

Answer 1

您没有注册附加财产，而是正常DependencyProperty。您应该使用DependencyProperty.RegisterAttached代替。此外，如果您的类仅包含附加属性，它也可以是静态类。它不必从DependencyObject

继承

public static class AttachedProperties
{
    public static readonly DependencyProperty TextProperty =
        DependencyProperty.RegisterAttached("Text", typeof(string), typeof(AttachedProperties), new PropertyMetadata(null, OnPropertyChangedCallback));

    public static void SetText(DependencyObject d, string value)
    {
        d.SetValue(TextProperty, value);
    }

    public static string GetText(DependencyObject d)
    {
        return d.GetValue(TextProperty) as string;
    }

    private static void OnPropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var richEditBox = d as RichTextBox;
        var textRange = new TextRange(richEditBox.Document.ContentStart, richEditBox.Document.ContentEnd);
        throw new NotImplementedException();
    }
}

使用附加属性时未调用OnPropertyChangedCallback

1 个答案: