Workaround: public Form1() { InitializeComponent(); this.radDropDownList1.AutoCompleteMode = AutoCompleteMode.Suggest; this.radDropDownList1.DropDownListElement.AutoCompleteSuggest.DropDownList.PopupOpened += DropDownList_PopupOpened; } private void DropDownList_PopupOpened(object sender, EventArgs e) { this.radDropDownList1.CloseDropDown(); }
The observed behavior with the second popup is by design, hence this request is being Declined. For reference, the MS ComboBox control has the same behavior. Please use the suggested approach to close the main popup when the auto complete gets opened. There is also another item regarding the same matter at the following link: http://feedback.telerik.com/Project/154/Feedback/Details/169297 It is with status approved, and if/once it gets considerable demand, we will consider changing the default behavior.