accessing control item when given inner template element

Question

I have a TreeviewItem with a style set to this

    <Style x:Key="TreeViewItemStyle" TargetType="TreeViewItem">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="TreeViewItem">
                        <StackPanel x:Name="stackpanel" Orientation="Horizontal">
                            <CheckBox x:Name="checkbox_treeview" Checked="treeView_AfterCheck" Unchecked="treeView_AfterCheck"/>
                            <Image x:Name="image_treeview" Width="16"/>
                            <local:WPFEditableTextBlock x:Name="label_TreeView" Text="{TemplateBinding Header}"/>
                        </StackPanel>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

I am able to access the checkbox of the template by doing this

TreeViewItem folderNode = new TreeViewItem();
Style style = this.FindResource("TreeViewItemStyle") as Style;
folderNode.Style = style;
ControlTemplate controlTemplate = folderNode.Template;
var templatedControl = folderNode.Template.LoadContent() as FrameworkElement;
CheckBox chbx = (CheckBox)templatedControl.FindName("checkbox_treeview");

once I am able to access this checkbox I have it go to the checked event handler. within that I want to be able to access the treeViewItem that contains that checkbox, but I can't figure out how to do this. Please help me out!!!

Answer 1

To access the treeViewItem from the checkbox defined in the template you could pass it in the Tag property from xaml like so:

 <ControlTemplate TargetType="TreeViewItem">
                    <StackPanel x:Name="stackpanel" Orientation="Horizontal">
                        <CheckBox x:Name="checkbox_treeview" Tag="{Binding RelativeSource={RelativeSource AncestorType={x:Type TreeViewItem}}}" Checked="treeView_AfterCheck" Unchecked="treeView_AfterCheck"/>
                        <Image x:Name="image_treeview" Width="16"/>
                        <local:WPFEditableTextBlock x:Name="label_TreeView" Text="{TemplateBinding Header}"/>
                    </StackPanel>
 </ControlTemplate>

and here how to retrieve it from the event handler:

private void treeView_AfterCheck(object sender, RoutedEventArgs e)
{
     var tvi = ((sender as CheckBox).Tag as TreeViewItem);
}