CheckComboBox Emulation

There are times when you may wish to have a combo box editor on your page that allows multiple selection. In the DevExpress web editors library, multiple item selection is built into the ASPxListBox editor by default, but the ASPxComboBox editor does not have this functionality. This demo illustrates how you can use a combination of the ASPxDropDownEdit and ASPxListBox editors to emulate a combo box that allows end-users to select multiple items within its dropdown list.

In this demo, a template of the DropDownWindowTemplate type is created within the ASPxDropDownEdit. This template contains an instance of the ASPxListBox editor, whose SelectionMode property is set to the CheckColumn value. Also, you can use the list box's built-in SelectAll feature (EnableSelectAll) and implement filtering of underlying data source values using the filter editor (ShowSearchUI).

The ASPxListBox editor's SelectedItems property allows you to access the collection of selected items. The ASPxDropDownEdit's Text property stores a list containing selected items (that is, values of their Text property), separated by semicolons. In addition to selecting items within the dropdown list, this demo allows end-users to select items by entering semicolon-separated series of an item text into the ASPxDropDownEdit edit box. If the text of an item that does not exist is entered, it is deleted from the edit box.