Project Description
The ColumnListBoxExtender is an Ajax Control Toolkit extender for the asp:ListBox control. It presents the options in X number of columns instead of one single column. Support for multiselect in combination with ctrl and/or shift is included as well as "mousedown drag selecting".


For the ColumnListBoxExtender to work, you must also reference the AjaxControlToolkit dll.
As for all Ajax Control Toolkit controls, the aspx page that hosts the ColumnListBoxExtender also needs an asp:ScriptManager control (directly or indirectly via a MasterPage).

Get started
Drop the dll-file of the ColumnListBox project in the bin folder of your Asp.NET WebSite project. Rebuild the project and the control should appear in the Visual Studio Toolbox. If not, follow these instructions.

Samples and Documentation
You can find live samples and documentation on how to configure the control at

Any feedback about the control, issues, examples of where and how it is used etc, is greatly appreciated. Especially testing the control on different OSs and different browsers. If you do, please report your results by making a comment to this workitem: Browser testing

The Ajax ColumnListBoxExtender was created by Dan Pettersson, visit his jQuerified homepage at and his blog on .NET at

Last edited Mar 20, 2009 at 1:31 PM by deap82, version 11