WPF 数据模板获取流文档

Question

我有两个DataTemplate用于我的EvenementViewModel，一个用于只读(LectureEvenement(，另一个用于写入(EditeurEvenement(。 根据 EvenementViewModel 状态选择模板。这些模板在选项卡控件中使用。

从代码隐藏(按钮单击(中，我想获取只读数据模板中的流文档。目标是打印流文档。

我需要帮助来获取 TabControl 的选定选项卡中的流文档的句柄。

有什么建议吗？

XAML 代码的某些部分。

<Window.Resources>
<DataTemplate x:Key="EditeurEvenement" DataType="{x:Type local:EvenementViewModel}">
<ScrollViewer Name="Conteneur" HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
<StackPanel MaxWidth="1000">
<Border BorderThickness="5" BorderBrush="#55CDD7E1">
<StackPanel Background="#55CDD7E1">
<!-- Centrale -->
<StackPanel DockPanel.Dock="Top" Margin="0,0,0,5" HorizontalAlignment="Left">
<TextBlock VerticalAlignment="Center"><Run Text="Centrale :" FontWeight="Bold"/></TextBlock>
<ComboBox MinWidth="160" ItemsSource="{Binding ListeCentrale}" DisplayMemberPath="Nom" SelectedItem="{Binding Centrale}"/>
</StackPanel>
...
</StackPanel>
</Border>
</StackPanel>
</ScrollViewer>
</DataTemplate>
<DataTemplate x:Key="LectureEvenement" DataType="{x:Type local:EvenementViewModel}">
<FlowDocumentScrollViewer VerticalScrollBarVisibility="Auto">
<FlowDocument FontFamily="Sergoe UI" FontSize="12px" Name="FdEvenement">
<Paragraph>
<!-- Centrale -->
<TextBlock Margin="0,0,0,5"><Run Text="Centrale : " FontWeight="Bold"/><Run Text="{Binding Centrale.Nom, Mode=OneWay}"/></TextBlock>
<LineBreak/>
...
</Paragraph>
</FlowDocument>
</FlowDocumentScrollViewer>
</DataTemplate>
<DataTemplate DataType="{x:Type local:EvenementViewModel}">
<ContentControl Content="{Binding}">
<ContentControl.Style>
<Style TargetType="{x:Type ContentControl}">
<Setter Property="ContentTemplate" Value="{StaticResource LectureEvenement}"></Setter>
<Style.Triggers>
<DataTrigger Binding="{Binding EstModifiable}" Value="True">
<Setter Property="ContentTemplate" Value="{StaticResource EditeurEvenement}"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</ContentControl.Style>
</ContentControl>
</DataTemplate>
</Window.Resources>
<TabControl x:Name="TcEvenements" ItemsSource="{Binding ListeOngletOuvert}" SelectedItem="{Binding OngletSelectionne}">
<TabControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding TitreTab}" Margin="0,0,5,0" VerticalAlignment="Center"/>
<Button CommandParameter="{Binding DataContext, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" Command="{Binding LancerFermer}">
<Image Source="Icone/icons8-delete-23.png" Width="15"/>
</Button>
</StackPanel>
</DataTemplate>
</TabControl.ItemTemplate>
</TabControl>

Answer 1

每当应用模板时，FlowDocumentScrollViewer元素都是TabControl的可视子元素。然后，您可以使用VisualTreeHelper类获取对它的引用：

private void Button_Click(object sender, RoutedEventArgs e)
{
FlowDocumentScrollViewer fdsv = FindVisualChild<FlowDocumentScrollViewer>(TcEvenements);
if (fdsv != null)
{
FlowDocument fd = fdsv.Document;
//...
}
}
private T FindVisualChild<T>(Visual visual) where T : Visual
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(visual); i++)
{
Visual child = (Visual)VisualTreeHelper.GetChild(visual, i);
if (child != null)
{
T correctlyTyped = child as T;
if (correctlyTyped != null)
{
return correctlyTyped;
}
T descendent = FindVisualChild<T>(child);
if (descendent != null)
{
return descendent;
}
}
}
return null;
}