CODEWITHSUNDEEP
c#wpfxamltreeviewitemtemplate
Dan PyongAn Byon
Dan PyongAn Byon

Reputation: 61

WPF TreeView ItemTemplate not applied to TreeViewItem

I have a TreeView and manually add two items (TreeViewItem) to it. And I want to apply ItemTemplate to those two items but it seems like the ItemTemplate is not applied to them. Actually I have deeper levels in the tree (so item1 and item2 each has a collection as ItemsSource, and there are more HierarchicalDataTemplates for them). But to demonstrate the first Template NOT being applied to the first-level items, I simplified the example. Below are the behind codes.

        TreeViewItem item1 = new TreeViewItem();
        TreeViewItem item2 = new TreeViewItem();
        trvRecordList.Items.Add(item1);
        trvRecordList.Items.Add(item2);

And here are my xaml codes. The HierarchicalDataTemplate is written in a correct place. 

                      <HierarchicalDataTemplate x:Key="My_Template">                                                      
                            <StackPanel Orientation="Horizontal">
                                <Image Source="Images/Star_Blue.png"
                                       Margin="0,0,4,0" Height="16" Width="16"/>
                                <TextBox Text="abcd"/>
                            </StackPanel>
                        </HierarchicalDataTemplate>


                      <TreeView Name="trvRecordList" Margin="2"
                              ItemTemplate="{StaticResource My_Template}">                           
                     </TreeView>

Upvotes: 1

Views: 1953

Answers (2)

Anand Murali
Anand Murali

Reputation: 4109

Since you are adding a list of TreeViewItem objects to your TreeView, My_Template will not be applied to it. If you check your output window, you would be getting an error as shown below

System.Windows.Data Error: 26 : ItemTemplate and ItemTemplateSelector are ignored for items already of the ItemsControl's container type; Type='TreeViewItem'

The solution is to apply My_Template to the ItemTemplate property of the TreeViewItem itself. Below are the modifications I've done to your code

        TreeViewItem item1 = new TreeViewItem();
        TreeViewItem item2 = new TreeViewItem();
        item1.Items.Add("");
        item1.Items.Add("");
        item1.ItemTemplate = FindResource("My_Template") as HierarchicalDataTemplate;

        item2.Items.Add("");
        item2.Items.Add("");
        item2.ItemTemplate = FindResource("My_Template") as HierarchicalDataTemplate;

        trvRecordList.Items.Add(item1);
        trvRecordList.Items.Add(item2);

Go through the below link to learn more about HierarchicalDataTemplate

http://blogs.msdn.com/b/mikehillberg/archive/2009/10/30/treeview-and-hierarchicaldatatemplate-step-by-step.aspx

Edit:

If you want to apply My_Template to the TreeView then try this code.

        trvRecordList.Items.Add("");
        trvRecordList.Items.Add("");

Upvotes: 1

ShadeOfGrey
ShadeOfGrey

Reputation: 1266

The ItemTemplate is for data objects. Check the remarks for ItemTemplate on MSDN.

TreeViewItem is container generated for each data item and is styled thru ItemContainerTemplate. ItemContainerTemplate on MSDN

Upvotes: 0

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