It is similar to a RadioButtonList control but occupies much less space on screen. The options are shown in a single-line picklist. They are contained in a ListItemCollection collection of the control.
The methods, properties and events of a DropDownList control are similar to a RadioButtonList control. It does not have the properties: CellPadding, CellSpacing, RepeatDirection, RepeatLayout, RepeatColumns, and TextAlign.
You can add items to a DropDownList control in the same 3 ways as for a RadioButtonList control: