FlowDocumentReader滚动到顶部

Question

如何滚动到FlowDocumentReader的顶部？

通过绑定来设置内容

<FlowDocumentReader Grid.Row="4" Grid.Column="0" Name="FlowDocumentPageViewer1" HorizontalAlignment="Stretch">
    <FlowDocumentReader.Document>
        <Binding ElementName="_this" Path="DocFlow" IsAsync="False" Mode="OneWay"/>
    </FlowDocumentReader.Document>                   
</FlowDocumentReader>

如果我向下滚动，然后绑定新内容，它不会滚动到顶部。

有了新内容，我想滚动到顶部。

根据Clemnes的评论，这将滚动到顶部

FlowDocumentPageViewer1.Document.BringIntoView();

现在我的问题是如何使调用自动化。

我不能把它放在get中，因为我不能把那个命令放在返回之后。

尝试了这两个事件，但未使用绑定更新触发

Loaded="FlowDocumentPageViewer1_loaded"  
SourceUpdated="FlowDocumentPageViewer1_loaded"

Answer 1

您可以创建设置原始Document属性并调用BringIntoView()的附加属性

public class FlowDocumentReaderEx
{
    public static readonly DependencyProperty DocumentProperty =
        DependencyProperty.RegisterAttached(
            "Document", typeof(FlowDocument), typeof(FlowDocumentReaderEx),
            new FrameworkPropertyMetadata(DocumentPropertyChanged));

    public static FlowDocument GetDocument(DependencyObject obj)
    {
        return (FlowDocument)obj.GetValue(DocumentProperty);
    }

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

    private static void DocumentPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
    {
        var flowDocumentReader = obj as FlowDocumentReader;

        if (flowDocumentReader != null)
        {
            flowDocumentReader.Document = e.NewValue as FlowDocument;

            if (flowDocumentReader.Document != null)
            {
                flowDocumentReader.Document.BringIntoView();
            }
        }
    }
}

现在，您可以像这样绑定此属性：

<FlowDocumentReader ...
    local:FlowDocumentReaderEx.Document="{Binding DocFlow, ElementName=_this}"/>