There are times when you might want to have a combo box editor on your page that allows for multiple selections.
In the DevExpress web editors library, multiple item selection is built in the ASPxListBox editor by default,
but the ASPxComboBox editor doesn't have it. 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 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.
The ASPxDropDownEdit's Text property stores a list containing the selected items (that is, the values of their Text property),
demimited by semicolons. In addition to selecting items within the dropdown list, this demo allows end-users to select items by entering a
semicolon-separated series of item texts in the ASPxDropDownEdit's edit box. If an item text is entered that doesn't exist,
it is deleted from the edit box.