How to: Add DropDownList Web Server Controls to a Web Forms Page
The process of adding a DropDownList Web server control to a page consists primarily of setting options that specify how items should be displayed and whether users can select multiple items.
To add a DropDownList Web server control to a Web Forms page
Type an
<asp:DropDownList>element into the page. For syntax, see DropDownList Web Server Control.Create items for the control in one of the following two ways:
By creating them as individual items. For details, see How to: Add Items in List Web Server Controls.
By binding data to the control. For details, see How to: Populate List Web Server Controls from a Data Source.