Inconsistent Expander State in RadTreeListView

[Jennifer]

We have a RadTreeListView where the IsExpanded property of the rows is bound to a property on row objects.  Sometimes, some of the expander triangles in the RadTreeListView look expanded, but their children are not visible.  Any idea what might be causing this or how to fix it? 

 

The attached image shows a small example.  The third row looks like it's expanded, but its child is not shown.  If you click the triangle, it collapses it; and if you click it again, it's then expanded properly with the child shown.

 

[Dilyan Traykov]

Hello Jennifer,

We're currently unaware of such an issue with the RadTreeListView control, but if you would provide a small sample project which demonstrates the issue, I'd be more than happy to further investigate and assist you.

Please let me know whether you would find this possible.

Regards,
Dilyan Traykov
Progress Telerik

[Jennifer]

I was not able to attach a zip file here, so I have opened a support ticket with it.

[Dilyan Traykov]

Hello Jennifer,

I'm also posting the solution here so that it is beneficial to the community.

As stated in the IsExpandedBinding and IsExpandableBinding article, binding to the IsExpanded property of TreeListViewRow items is not fully supported. Using the IsExpandedBinding property instead solved the issue in this particular case.

<telerik:RadTreeListView ItemsSource="{Binding Rows}" IsExpandedBinding="{Binding IsExpanded, Mode=TwoWay}" ...

I do hope other clients who come across a similar issue find this information helpful.

Regards,
Dilyan Traykov
Progress Telerik