MemberShip创建一个新角色

      1.在MemberShip的aspnet_Roles表里面添加一个新角色的代码：

           System.Web.Security.Roles.CreateRole("Provider");
            if (System.Web.Security.Roles.RoleExists("Provider"))
            {
                Response.Write("<script>alert('创建成功!')</script>");
            }

            说明：在aspnet_Roles添加一个"Provider"角色。
      2.在MemberShip判断该账号是否存在的代码：
            //查找该账号是否存在

           MembershipUserCollection a = Membership.FindUsersByEmail("账号(如邮箱)");

            if (a.Count == 1)
            {
                foreach (MembershipUser ms in a)
                {
                    string userName = ms.UserName.ToString();
                     //如果存在该账号，给该账号分配"Provider"权限。
                    System.Web.Security.Roles.AddUserToRole(userName,"Provider");
                     if (System.Web.Security.Roles.GetRolesForUser(userName!= null)
                    {
                        Response.Write("<script>alert('配置成功!')</script>");
                    }
                     else
                     {
                         Response.Write("<script>alert('配置失败!')</script>");

                      }
                        
                }

            }
            else
            {
                Response.Write("<script>alert('账号不存在!')</script>");
            }