UWP：在TreeNode中将文本设置为粗体

Question

I am following Microsoft's documentation to implement a TreeView in a Universal Windows Platform app in C++ . I have successfully been able to create a tree view with one node using the following codes:

XAML:

<TreeView x:Name="treeSolution"></TreeView>

C++:

TreeViewNode ^treeNode = ref new TreeViewNode();
treeNode->Content = "Hello";
treeSolution->RootNodes->Append(treeNode);

Now, I want to set the text to bold. I tried the following:

TextBlock ^textBlock = ref new TextBlock();
textBlock->Text = "Hello";
textBlock->FontWeight = Windows::UI::Text::FontWeights::Bold;
treeNode->Content = textBlock;
treeSolution->RootNodes->Append(treeNode);

The code displays Windows.UI.Xaml.Controls.TextBlock instead of Hello in bold.

The documentation says that In Windows 10, version 1803, you have to retemplate the TreeView control and specify a custom ItemTemplate if your content is not a string. It then gives a complex example using the Music and Picture library.

Could somebody provide a simple example of how to display the text in bold? Thanks.

Answer 1

You have to provide a custom style for the whole control in XAML to be able to set the TreeViewItemDataTemplate :

<DataTemplate x:Key="TreeViewItemDataTemplate">
    <Grid Height="44">
        <TextBlock
            Text="{Binding Content}"
            HorizontalAlignment="Left"
            VerticalAlignment="Center"
            Style="{ThemeResource BodyTextBlockStyle}"
            FontWeight="Bold" />
    </Grid>
</DataTemplate>

<Style TargetType="TreeView">
    <Setter Property="IsTabStop" Value="False" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TreeView">
                <TreeViewList x:Name="ListControl"
                              ItemTemplate="{StaticResource TreeViewItemDataTemplate}"
                              ItemContainerStyle="{StaticResource TreeViewItemStyle}"
                              CanDragItems="True"
                              AllowDrop="True"
                              CanReorderItems="True">
                    <TreeViewList.ItemContainerTransitions>
                        <TransitionCollection>
                            <ContentThemeTransition />
                            <ReorderThemeTransition />
                            <EntranceThemeTransition IsStaggeringEnabled="False" />
                        </TransitionCollection>
                    </TreeViewList.ItemContainerTransitions>
                </TreeViewList>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>