[Solved] TreeView in ItemTemplate is blank after binding...

[Peter From LA]

I used the Combobox/Template example to build a RadComboBox with a RadTreeView as an ItemTemplate, but instead of a SqlDataSource I bound the tree in C# using a List<object>. The same tree works fine when it is by itself and shows all the data correctly, but when it is inside of the Item it is BLANK - the drop down is empty.

this is my front end code:

<telerik:RadComboBox
    ID="rcbDrawing"
    Width="205px"
    Height="300px"
    AllowCustomText="true"
    EmptyMessage="Select A Drawing"
    runat="server"
    Skin="Outlook"
    >
    <ItemTemplate>
        <div onclick="StopPropagation(event)">
            <telerik:RadTreeView
                ID="treeDrawings"
                runat="server"
                DataTextField="Name"
                DataValueField="ID"
                DataFieldID="ID"
                DataFieldParentID="ParentID"
                Skin="Outlook"
                OnClientNodeClicking="OnTreeNodeClicking"
                ></telerik:RadTreeView>
        </div>
    </ItemTemplate>
    <Items>
        <telerik:RadComboBoxItem />
    </Items>
</telerik:RadComboBox>

This is how I do the binding:

RadTreeView treeDrawings = (RadTreeView)rcbDrawing.Items[0].FindControl("treeDrawings");
DrawingsCollection d = DrawingsCollection.GetByClientID(PageUser);
treeDrawings.DataSource = d;
treeDrawings.DataBind();
treeDrawings.ExpandAllNodes();

Am I doing anything wrong?

[Ivana]

Hi Peter,

Please take a look at the help article below. There you will find examples of how to bind the RadTreeView to an Array.

• http://www.telerik.com/help/aspnet-ajax/treeview-data-binding-array.html

Also make sure you have set the properties DataFieldID  and  DataFieldParentID  of the RadTreeView correct as noted in the help article.

All the best,

Ivana Gjorgeva

the Telerik team

[Ivan Zhekov]

Hello, Peter.

With this release: 2013 Q1, we are releasing the DropDownTree -- a control designed to work in a manner similar to TreeView in ComboBox.

Since you have such scenario, you might be interested. You can check the examples here -- http://demos.telerik.com/aspnet-ajax-beta/DropDownTree/Examples/Overview/Defaultcs.aspx -- or later on at the official (non-beta) site.

Regards,
Ivan Zhekov
the Telerik team