WPF C＃：如何从HierarchicalDataTemplate获取treeviewitem标头

Question

I am using HierarchicalDataTemplate to build my TreeView dynamicaly and don't know how to get the header of the selected item from treeview.

I tried to get it by the TreeViewItem.Selected event.

    private void TreeViewItem_OnItemSelected(object sender, RoutedEventArgs e)
    {
        TreeViewItem item = e.OriginalSource as TreeViewItem;
        string name = item.Header.ToString();
    }

but 'item.Header' is of type Node

this is my XAML-code:

<Window x:Class="MaschinenStoppScheduler.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:MyNamespace="clr-namespace:MaschinenStoppScheduler"
    Title="MaschinenStoppScheduler" Height="500" Width="900" Loaded="Window_Loaded_1">
<Window.DataContext>
    <MyNamespace:MainWindowVM />
</Window.DataContext>
<Grid>
    <TreeView x:Name="TreeViewGroups" TreeViewItem.Selected ="TreeViewItem_OnItemSelected"  
        ItemsSource="{Binding RootNodes}" HorizontalAlignment="Left" Margin="20,28,0,25" 
        VerticalAlignment="Stretch" Width="181" SelectedItemChanged="TreeViewGroups_SelectedItemChanged">
        <ItemsControl.ItemContainerStyle>
            <Style
            TargetType="{x:Type TreeViewItem}">
                <Setter Property="IsExpanded" Value="{Binding IsExpanded}" />
            </Style>
        </ItemsControl.ItemContainerStyle>
        <ItemsControl.ItemTemplate>
            <HierarchicalDataTemplate DataType="{x:Type MyNamespace:Node}" ItemsSource="{Binding Children}">
                <StackPanel Orientation="Horizontal" HorizontalAlignment="Left">
                    <TextBlock Text="{Binding Name}" />
                </StackPanel>
            </HierarchicalDataTemplate>
        </ItemsControl.ItemTemplate>
    </TreeView>
</Grid>

Answer 1

Yes, the selected item will be one of the items in RootNodes. Cast it to that type. Node , it seems to be. The header will be whatever property of that class you use for the header -- Name , it looks like.

private void TreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    var treeView = sender as TreeView;

    var selectedNode = treeView.SelectedItem as Node;

    TreeViewItem tvi = treeView.ItemContainerGenerator.ContainerFromItem(treeView.SelectedItem) as TreeViewItem;
}

Node is the class contained in the collection you bound to ItemsSource on the TreeView . I've also included code demonstrating how to get the selected TreeViewItem .