问如何扩展/定制MVC4互联网应用程序网络安全/简单成员关系

EN

    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public ActionResult Register(RegisterModel model)
    {
        if (ModelState.IsValid) //TODO Change this to use a worker to send emails.
        {
            // Check if email exists already before creating new user
            using (UsersContext db = new UsersContext())
            {
                UserProfile email = db.UserProfiles.FirstOrDefault(u => u.Email.ToLower() == model.Email.ToLower());
                UserProfile uName =
                    db.UserProfiles.FirstOrDefault(u => u.UserName.ToLower() == model.UserName.ToLower());

                // Attempt to register the user
                try
                {
                    if (email == null && uName == null && this.IsCaptchaVerify("Captcha is not valid"))
                    {
                        bool requireEmailConfirmation = !WebMail.SmtpServer.IsEmpty();
                        string confirmationToken = WebSecurity.CreateUserAndAccount(model.UserName, model.Password, new
                        {
                            FirstName = model.FirstName,
                            LastName = model.LastName,
                            Email = model.Email                               
                        },
                        requireEmailConfirmation);
                        if (requireEmailConfirmation)
                        {
                            EmailViewModel eml = new EmailViewModel
                                                     {
                                                         ToEmail = model.Email,
                                                         Subject = "Confirmez votre inscription",
                                                         FirstName = model.FirstName,
                                                         LastName = model.LastName,
                                                         Body = confirmationToken
                                                     };

                            UserMailer.ConfirmRegistration(eml).SendAsync();

                            Response.Redirect("~/Account/Thanks");                            
                        }
                        else
                        {
                            WebSecurity.Login(model.UserName, model.Password);
                            Response.Redirect("~/");
                        }                           
                    }
                    else
                    {
                        if (email != null)
                            ModelState.AddModelError("Email", "Email address already exists. Please enter a different email address.");

                        if (uName != null)
                            ModelState.AddModelError("UserName", "User Name already exists. Please enter a different user name.");

                        if (!this.IsCaptchaVerify("Captcha is not valid"))
                            TempData["ErrorMessage"] = "Captcha is not valid";
                    }

                }
                catch (MembershipCreateUserException e)
                {
                    ModelState.AddModelError("", ErrorCodeToString(e.StatusCode));
                }
            }
        }

        // If we got this far, something failed, redisplay form
        return View(model);
    }