Richard is correct. Our
RadTextBox control wraps the generic
TextBox provided with the .NET and uses its auto complete mechanism, and there is no way you can access the auto complete dropdown. A quick Google search shows some workarounds though (note that these have not been tested and are not supported by Telerik):
http://social.msdn.microsoft.com/Forums/en/winformsdesigner/thread/f88f37c9-95f9-4f2f-84b5-e262f49a009d
http://stackoverflow.com/questions/4820429/combo-box-drop-down-width-on-suggest
Hope this.
All the best,
Ivan Todorov
the Telerik team
Q3’10 SP1 of RadControls for WinForms is available for
download; also available is the Q1'11
Roadmap for Telerik Windows Forms controls.