无法将 FlowDocumentScrollViewer 动态绑定到 FlowDocument

如何解决无法将 FlowDocumentScrollViewer 动态绑定到 FlowDocument

我创建了一个自定义控件（命名为 TextBlockHtml，它继承自标签），我添加了一个依赖属性（命名为 flowDocument[its transfer aassigned document]）

  <Style targettype="{x:Type local:TextBlockHtml}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate targettype="{x:Type local:TextBlockHtml}">
                <Border>
                    <TextBlock HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" 
                               Background="{TemplateBinding Background}" FontSize="{TemplateBinding FontSize}" 
                               Foreground="{TemplateBinding Foreground}" Text="{Binding Path=Content,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type local:TextBlockHtml}}}"/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>

    <Setter Property="ToolTip">
        <Setter.Value>
            <ToolTip>
                <ToolTip.Style>
                    <Style targettype="ToolTip">
                        <Setter Property="ContentTemplate">
                            <Setter.Value>
                                <DataTemplate>
                                    <FlowDocumentScrollViewer x:Name="PART_FlowDocument"  VerticalScrollBarVisibility="Hidden"  Document="{Binding Path=flowDocument,AncestorType={x:Type local:TextBlockHtml}}}">
                                    </FlowDocumentScrollViewer>
                                </DataTemplate>
                            </Setter.Value>
                        </Setter>
                    </Style>

                </ToolTip.Style>

            </ToolTip>
        </Setter.Value>
    </Setter>
</Style>

问题在于，当我在一个容器中放置多个自定义控件时，即使我指定了不同的 Documents，所有自定义控件的 Tooltip 都会与第一个显示工具提示的控件相同。

MainWindows.xaml

        <local:TextBlockHtml  Content="Table Demo"   flowDocument="{StaticResource TestFlowDocumentFlex}"    />
    <local:TextBlockHtml  Content="List Demo"    flowDocument="{StaticResource TableResource}"   />
    <local:TextBlockHtml  Content="Html Test 1"  flowDocument="{StaticResource ReportStructure}"   />