Note that in multiple selection mode, all ASPxListBox's features are supported, except loading items on demand via callbacks (which the editor's EnableCallbackMode and CallBackPageSize properties usually control). The DevExpress ASP.NET Autocomplete Combo Box (ASPxComboBox) control allows content (the item list) to be updated via callbacks using the PerformCallback client method.In this demo, the 'City' combo box is populated on the fly with city names that correspond to the currently selected country from the 'Country' combo box. To enable this feature, set the ASPxListBox's EnableSelectAll option to true. When the CheckColumn selection mode is enabled for the list box, end-users can select all items using the 'Select All' check box at the top of the list box. SelectItems, UnselectItems client methods). Also, to apply an item selection on the client side, use a specific client API (the editor's GetSelectedItems, Use the SelectedItems or SelectedIndices properties to obtain a collection of selected items.

When Multiple Selection is enabled, use the item's Selected property to specify individual items' selection state.

CheckColumn - End-users can select multiple items within the editor by clicking list items.

Multiple - End-users can select multiple items within the editor by clicking list items while pressing Ctrl (to add an individual item) or Shift (to select a range of items).

Single - End-users can select only one item within the editor.Depending on this property's setting, the following selection modes are available within the ASPxListBox editor:

The editor's SelectionMode property controls selection behavior. The DevExpress ASP.NET List Box ( ASPxListBox) editor allows you to select multiple list items at the same time.

Comboboxedit devexpress