I have a Windows application written in VB.Net.  It has a RadDropDownList control that has Items added to it at Design time.

I would like to Filter the items in the RadDropDownList control or disable/enable some items in the RadDropDownList control depending on the data in the other controls on the WinForm.

I have tried looking at the documentation but it is not clear on how to filter the RadDropDownList or find some items to be enabled or disabled in the RadDropDownList when the control has items added at design time not at runtime.

I am using version 2015.3.1104.40 of the RadDropDownList.

 Please help.  Thanks!

Hello Keith,

Thank you for writing.

Filtering the items or disabling some items does not depend on whether the RadListDataItem has been added in the designer or at run-time.

Filtering can be set by using a predicate and its Filter property or via a FilterExpression, more information is available here: http://docs.telerik.com/devtools/winforms/dropdown,-listcontrol-and-checkeddropdownlist/dropdownlist/filtering.html.

I am sending you attached an example project which I believe should get you going. In the sample, the items are filtered depending on the value of a RadToggleSwitch control. I am also sending you a gif file showing the result on my end.

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik