public void CreateTutorInformation(User tutor, ITutor information)
        {
            Message = "";
            Succeed = false;
            using (var db = new BaseDbContext())
            {
                var contextUser = db.Users.Find(tutor.Id);
                if (contextUser == null)
                {
                    Message = "未能从数据库中找到用户";
                    return;
                }
                var info = new TutorInformation {
                    Tutor = contextUser,
                    Introduction = information.TutorIntroduction,
                    Position = information.TutorPosition,
                    Avatar = information.TutorAvatar };
                db.TutorInformations.Add(info);
                try
                {
                    db.SaveChanges();
                }
                catch (Exception)
                {
                    Message = "出现错误";
                    return;
                }

                Succeed = true;
                return;
            }
        }
        public async System.Threading.Tasks.Task<ActionResult> TutorCreate(CreateTutorViewModel model)
        {
            if (ModelState.IsValid)
            {
                if (Request.Files.Count != 1)//如果文件列表为空则返回
                {
                    ViewBag.Alert = "请检查上传文件!";

                    return View();
                }

                var file = Request.Files[0];//只上传第一个文件

                var user = Models.User.Create(model.Email, model.DisplayName);
                var result = await UserManager.CreateAsync(user, model.Password);
                if (result.Succeeded)
                {
                    //为账户添加角色
                    var roleName = "Tutor";
                    ApplicationRoleManager roleManager = new ApplicationRoleManager(new RoleStore<IdentityRole>(db));

                    //判断角色是否存在
                    if (!roleManager.RoleExists(roleName))
                    {
                        //角色不存在则建立角色
                        await roleManager.CreateAsync(new IdentityRole(roleName));
                    }
                    //将用户加入角色
                    await UserManager.AddToRoleAsync(user.Id, roleName);

                    // 有关如何启用帐户确认和密码重置的详细信息,请访问 http://go.microsoft.com/fwlink/?LinkID=320771
                    // 发送包含此链接的电子邮件
                    // string code = await UserManager.GenerateEmailConfirmationTokenAsync(user.Id);
                    // var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: Request.Url.Scheme);
                    // await UserManager.SendEmailAsync(user.Id, "确认你的帐户", "请通过单击 <a href=\"" + callbackUrl + "\">這裏</a>来确认你的帐户");

                    var avatar = Material.Create(user.DisplayName, MaterialType.Avatar, file, db);
                    if (avatar == null)
                    {
                        TempData["ALert"] = "请检查上传文件!";
                        return View(model);
                    }
                    var tutor = new TutorInformation { Id = Guid.NewGuid(), Tutor = db.Users.Find(user.Id), Avatar = avatar, Position = model.Position, Introduction = model.Introduction };
                    db.TutorInformations.Add(tutor);
                    db.SaveChanges();
                    ViewBag.Alert = "操作成功!";

                    return View();
                }
            }
            ViewBag.Alert = "操作失败!";

            return View();
        }