评估ASP.NET 5 / MVC6 Identity Custom Profile数据属性

Question

I have made a sample web app named ShoppingList using the asp.net 5 web application template (Mvc6/MVC core/Asp.net-5). I wanted to extend the user profile with a custom field name DefaultListId.

The ApplicationUser.cs:

namespace ShoppingList.Models
{
    // Add profile data for application users by adding properties to the ApplicationUser class
    public class ApplicationUser : IdentityUser
    {
        public int DefaultListId { get; set; }
    }
}

In the home controller I would like to access the data stored for this property. I tried:

namespace ShoppingList.Controllers
{
    public class HomeController : Controller
    {
       private UserManager<ApplicationUser> userManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));

        public IActionResult Index()
        {
           var userId = User.GetUserId();
           ApplicationUser user = userManager.FindById(userId);

            ViewBag.UserId = userId;
            ViewBag.DefaultListId = user.DefaultListId;

            return View();
        }
    //other actions omitted for brevity

However I get the following errors:

Severity Code Description Project File Line Suppression State Error CS7036 There is no argument given that corresponds to the required formal parameter 'optionsAccessor' of 'UserManager.UserManager(IUserStore, IOptions, IPasswordHasher, IEnumerable>, IEnumerable>, ILookupNormalizer, IdentityErrorDescriber, IServiceProvider, ILogger>, IHttpContextAccessor)' ShoppingList.DNX 4.5.1, ShoppingList.DNX Core 5.0 C:\\Users\\OleKristian\\Documents\\Programmering\\ShoppingList\\src\\ShoppingList\\Controllers\\HomeController.cs 15 Active

And...

Severity Code Description Project File Line Suppression State Error CS1061 'UserManager' does not contain a definition for 'FindById' and no extension method 'FindById' accepting a first argument of type 'UserManager' could be found (are you missing a using directive or an assembly reference?) ShoppingList.DNX 4.5.1, ShoppingList.DNX Core 5.0 C:\\Users\\OleKristian\\Documents\\Programmering\\ShoppingList\\src\\ShoppingList\\Controllers\\HomeController.cs 20 Active

Answer 1

You should not instantiate your own UserManager , like ever. And it's actually pretty hard to do so, since it requires you to pass in a lot of arguments to the constructor (and most of those things are also very difficult to set up properly).

ASP.NET Core makes extensive use of dependency injection, so you should just set up your controller in a way that it receives the user manager automatically. That way, you don't have to worry about creating the user manager:

public class HomeController : Controller
{
    private readonly UserManager<ApplicationUser> userManager;

    public HomeController (UserManager<ApplicationUser> userManager)
    {
        this.userManager = userManager;
    }

    // …
}

However, in order to do that, you first need to set up ASP.NET Identity to actually know about your ApplicationUser and make it be used for storing your user identities. To do that, you need to modify the Startup class. In the ConfigureServices method, you need to change the AddIdentity call to make it reference your actual types:

services.AddIdentity<ApplicationUser, IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultTokenProviders();

IdentityRole here refers to the standard role type used by ASP.NET Identity (since you don't need a custom one). As you can see, we also reference a ApplicationDbContext there which is the entity framework database context for your modified identity model; so we need to set up that one too. In your case, it could just look like this:

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);

        // here you could adjust the mapping
    }
}

This will make sure that the ApplicationUser entity is actually stored properly in the database. We're almost done, but we now just need to tell Entity Framework about this database context as well. So again in the ConfigureServices method of your Startup class, make sure to adjust the AddEntityFramework call to also set up the ApplicationDbContext database context. If you have other database contexts, you can just chain these:

services.AddEntityFramework()
    .AddSqlServer()
    .AddDbContext<IdentityContext>(opts => opts.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]))
    .AddDbContext<DataContext>(opts => opts.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));

And that's it! Now Entity Framework knows about the new user entity and properly maps it to the database (including your new property), and ASP.NET Identity also knows about your user model and will use that one for everything it does, and you can have the UserManager injected into controllers (or services, or whatever) to do stuff.

---

As for your second error, you get this because the user manager does not have a FindById method; it only as a FindByIdAsync method. You will see this actually in a lot of places with ASP.NET Core that there are only asynchronous methods, so embrace it and start making your method asynchronous as well.

In your case, you would need to change the Index method like this:

// method is async and returns a Task
public async Task<IActionResult> Index()
{
    var userId = User.GetUserId();

    // call `FindByIdAsync` and await the result
    ApplicationUser user = await userManager.FindByIdAsync(userId);

    ViewBag.UserId = userId;
    ViewBag.DefaultListId = user.DefaultListId;

    return View();
}

As you can see, it does not require many changes to make the method asynchronous. Most of it stays just the same.