The Login.MembershipProvider property contains the name of the data provider that provides the authentication information for the System.Web.UI.WebControls.Login control. Valid membership provider names are defined in the <membership> element in your application's Machine.config or Web.config file.

If you do not set the Login.MembershipProvider property, it will always return string.Empty.

For more information, see the System.Web.Security.Membership class.

This property cannot be set by themes or style sheet themes. For more information, see System.Web.UI.ThemeableAttribute and ASP.NET Themes Overview.