使用导航属性扩展ASP.Net Identity

Question

Just recently started out to play with ASP.Net Identity in VS2013. I fired up a MVC5 project and are using the default template for it, with individual account. I am trying to extend the ApplicationUser class which is inherited from IdentityUser withe the following fields:

//this is my code first entity
public class ApplicationUser : IdentityUser
{
    public string Name { get; set; }
    public string EmailAddress { get; set; }
    public virtual SellingLocation Location { get; set; }
}

I have extended the Register.cshtml with textboxes for Name and EmailAddress, updated the registerviewmodel and added a list with all SellingLocation to populate a drop down list with it.

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

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

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

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

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

    [Display(Name = "Försäljningställe")]
    public int SellingLocationId { get; set; }

    public List<SellingLocationViewModel> SellingLocations { get; set; }
}

And the Register.cshtml code for the drop down:

<div class="form-group">
    @Html.LabelFor(m => m.SellingLocationId, new { @class = "col-md-2 control-label" })
    <div class="col-md-10">
        @Html.DropDownListFor(m => m.SellingLocationId, new SelectList(Model.SellingLocations, "Id", "Name"))
    </div>
</div>

The problem is in the account controller. When I try to add this new user a new copy of the SellingLocation is created (a new row in the database) instead of just adding a reference (foreign key) to the row which the selected value in the dropdown list was pointing to. What am I doing wrong?

// GET: /Account/Register
    [AllowAnonymous]
    public ActionResult Register()
    {
        var regvm = new RegisterViewModel();
        regvm.SellingLocations = GetSellingLocations();
        return View(regvm);
    }
    private List<SellingLocationViewModel> GetSellingLocations()
    {
        return Mapper.Map<List<SellingLocation>, List<SellingLocationViewModel>>(db.SellingLocations.ToList());
    }

        //
    // POST: /Account/Register
    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Register(RegisterViewModel model)
    {
        if (ModelState.IsValid)
        {
            //get the SellingLocation from the id from the selected value in dropdown
            var sellingloc = db.SellingLocations.Find(model.SellingLocationId);
            //creating user object, adding new data
            var user = new ApplicationUser() { UserName = model.UserName, Name = model.Name, EmailAddress = model.EmailAddress, Location = sellingloc };
            var result = await UserManager.CreateAsync(user, model.Password);
            //this will create a new row in SellingLocations, not just add a reference in AspNetUsers to the old row as expected.
            if (result.Succeeded)
            {
                await SignInAsync(user, isPersistent: false);
                return RedirectToAction("Index", "Home");
            }
            else
            {
                AddErrors(result);
            }
        }

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

Answer 1

You need a SellingLocationId in ApplicationUser and configure your foreign key relationship. When you create a new ApplicationUser you just fill in the SellingLocationId and not the virtual object Location . Location is filled in by EF after the Insert or when you query for a new ApplicationUser .

Also, for the SellingLocation to be duplicated in the database that must mean that SellingLocationID is not a unique ID. It needs to be.

Answer 2

I found the problem. I was using two different context objects, one for the UserManager and one for looking up the SellingLocation object in my Register post method.

Changing the constructor of the AccountController and catching the reference to the context passed into the UserStore which is passed into the UserManager fixed the problem. The code in the question works now when the db object is the reference to the context in UserManager.