CreateUser adds a new user to the data store and returns a MembershipUser object for the newly created user. If the user creation fails, a MembershipCreateUserException is thrown. You can retrieve a MembershipCreateStatus value from the StatusCode property of the MembershipCreateUserException that indicates why user creation failed.
Once a membership user has been created and you have a reference to a MembershipUser object for that user, you can modify the settings for that user with the MembershipUser public methods, such as ChangePasswordQuestionAndAnswer for applications where RequiresQuestionAndAnswer is true, or by setting the property values of the MembershipUser object and passing them to the UpdateUser method.
If a user already exists in the data source for the application, you can obtain a MembershipUser object for the existing user with the GetUser method.
The SqlMembershipProvider provides an option to require a unique e-mail address for each user. If the RequiresUniqueEmail property is true, you will need to use one of the CreateUser overloads that allows you to specify an e-mail address for the user being created. Otherwise, a MembershipCreateUserException will be thrown.
Leading and trailing spaces are trimmed from all parameter values.