在mvc5中添加一个额外的字段来注册表单c＃

Question

所以我将我的MVC应用程序链接到现有数据库，并且我一直在尝试根据我现有的数据库AspNetUsers表添加其他注册字段。

我需要在注册页面中包含一个包含公司名称的下拉列表。我已将此字段添加到RegisterViewModel并将SelectList添加到AccountController和Register视图，但应用程序仍在中断。

任何有关如何实现这一目标的帮助将不胜感激。

的AccountController：

        PosworxDBEntities db = new PosworxDBEntities();
        PosworxWebEntities db_ = new PosworxWebEntities();
        [AllowAnonymous]
        public ActionResult Register()
        {
            ViewBag.CustomerID = new SelectList(db_.Customers, "CustomerID", "CustomerName");
            return View();
        }

        //
        // POST: /Account/Register
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Register(RegisterViewModel model)
        {
            AspNetUser users = new AspNetUser(); 
            if (ModelState.IsValid)
            {
                var user = new ApplicationUser { UserName = model.Email, Email = model.Email};
                var result = await UserManager.CreateAsync(user, model.Password);
                if (result.Succeeded)
                {
                    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>");
                    ViewBag.CustomerID = new SelectList(db_.Customers, "CustomerID", "CustomerCompanyName", users.Id);

                    return RedirectToAction("Index", "Home");
                }
                AddErrors(result);
            }

AccountViewModel：RegisterViewModel

public class RegisterViewModel
    {
        [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; }

        public string CustomerID { get; set; }
    }

观点：

    <div class="form-group">
        <div class="col-md-3">
            @Html.LabelFor(m => m.CustomerID)
        </div>
        <div class="col-md-9">
            @Html.DropDownList("CustomerID", null, htmlAttributes: new { @class = "form-control" })
        </div>
    </div>