Question

我对此有点挠头。有时，此代码有效，我无法弄清楚为什么现在出现此错误。该错误显示在Visual Studio的剃须刀页面上。我需要从此下拉列表中获取的项目显示在帖子中。是否出于某种原因又回到了认为需要重新填充列表的观点？当然不会保存任何东西。我的调试显示

之后到了那里

await this.UserManager.AddToRoleAsync(user.Id, model.UserRoles);

它说：这是该线程从当前函数返回时要执行的下一条语句。在dropdownList旁边。控制器具有AddressId。该表格正确填充了下拉菜单。这是在Submit上发生的。

下面是我的控制器，viewModel和probem字符串

public class RegisterUserViewModel
{
    public static RegisterUserViewModel GetCompanyId(string userId, CustomerEntities db)
    {
        var qCust = from ad in db.Addresses

                    join anu in db.Users on ad.AddressId equals anu.AddressId
                    join cus in db.CompanyNames on ad.CompanyId equals cus.CompanyId
                    where (anu.AspNetUsersId == userId)
                    select new RegisterUserViewModel()
                    {
                        UserId = userId,
                        CompanyId = cus.CompanyId,
                        AddressId = ad.AddressId
                    };

        var result = qCust.SingleOrDefault();

        if (result != null)
        {
            result.Addresses = db.Addresses.Where(a => a.CompanyId == result.CompanyId);
        };

        return result;
    }

    [Required]
    [Display(Name = "User Name")]
    public string UserName { get; set; }

    [Required]
    [EmailAddress]
    [Display(Name = "Email")]
    public string Email { get; set; }

    [Required]
    [StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]
    [DataType(DataType.Password)]
    [Display(Name = "Password")]
    public string Password { get; set; }

    [DataType(DataType.Password)]
    [Display(Name = "Confirm password")]
    [Compare("Password", ErrorMessage = "The password and confirmation password do not match.")]
    public string ConfirmPassword { get; set; }

    [Required]
    [Display(Name = "User Address")]
    public int AddressId { get; set; }

    [Required]
    [Display(Name = "User Roles")]
    public string UserRoles { get; set; }

    public string UserId { get; set; }
    public int CompanyId { get; set; }
    public virtual IEnumerable<Addresses> Addresses { get; set; }
}

控制器：

        [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> RegisterUser(RegisterUserViewModel model)
    {
        if (ModelState.IsValid)
        {
            var user = new Models.ApplicationUser { UserName = model.UserName, Email = model.Email, AddressId = model.AddressId, CompanyId = model.CompanyId };
            var result = await UserManager.CreateAsync(user, model.Password);
            if (result.Succeeded)
            {
                var UserId = User.Identity.GetUserId();
                //await SignInManager.SignInAsync(user, isPersistent: false, rememberBrowser: false);

                // For more information on how to enable account confirmation and password reset please visit http://go.microsoft.com/fwlink/?LinkID=320771
                // Send an email with this link
                // 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, "Confirm your account", "Please confirm your account by clicking <a href=\"" + callbackUrl + "\">here</a>");
                //Assign Role to user Here   
                await this.UserManager.AddToRoleAsync(user.Id, model.UserRoles);
                var viewModel = new Users();
                {
                    viewModel.UsersId = Convert.ToString(Guid.NewGuid());
                    viewModel.Email = model.Email;
                    viewModel.FirstName = model.UserName;
                    viewModel.AspNetUsersId = user.Id;
                    viewModel.CreatedDate = System.DateTime.Now;
                    viewModel.UpdatedDate = System.DateTime.Now;
                };
                UsersBusinessModels register = new UsersBusinessModels();
                var results = await register.insertUser(viewModel);
                return RedirectToAction("AddUsers", "Customer", new { UserId });
            }
            ViewBag.Name = new SelectList(context.Roles.Where(u => !u.Name.Contains("Admin"))
                                      .ToList(), "Name", "Name");
            AddErrors(result);
        }

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

问题字符串：

 @Html.DropDownList("AddressId", new SelectList(Model.Addresses, "AddressId", "LocationName"), " Select Location user belongs to ", new {@id = "selection", @class = "form-control" })

我在页面底部也有这个

<script type="text/javascript">

    window.onload = function () { document.getElementById("selection").selectedIndex = 0; 

</script>

更新：我主要关心的还是我的问题是，当发布具有在数据库中生成记录所需的一切时，为什么为什么要回到视图呢？偶尔我会绊倒一些事情。这是那些时代之一。只是在寻找可能导致该问题的原因，或者我在这段代码中有什么是有效的-差不多一年前，当我编写该代码时，它现在无效了？

更新：添加get操作。注意：GET没有问题，因为它最初显示的表单没有问题。只有Post出错。

        // GET: /Account/RegisterUser
    [AllowAnonymous]
    public ActionResult RegisterUser(string userId)
    {
        ViewBag.Name = new SelectList(context.Roles.Where(u => !u.Name.Contains("Admin"))
                                        .ToList(), "Name", "Name");

        RegisterUserViewModel modelInstance = RegisterUserViewModel.GetCompanyId(userId, db);


        if (modelInstance == null)
        {
            return RedirectToAction("AddUsers", "Customer");
        }
        return View(modelInstance);
    }

System.ArgumentNullException：'值不能为null。参数名称：项目

0 个答案: