ASP.NET Core 2 导致 SignInManager 依赖项注入失败

Question

I'm trying to get access to Microsoft.AspNetCore.Identity.SignInManager in one of my classes that is not a controller.

In Startup.ConfigureServices() I have:

services.AddIdentity<IdentityUser, IdentityRole>();

In my class I have:

public class Auth : IAuth
{
    ...
    private readonly SignInManager<IdentityUser> _signInManager;

    public Auth(..., SignInManager<IdentityUser> signInManager)
    {
    }
}

And I get this exception:

An unhandled exception occurred while processing the request. InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.IUserStore 1[Microsoft.AspNetCore.Identity.IdentityUser]' while attempting to activate 'Microsoft.AspNetCore.Identity.AspNetUserManager 1[Microsoft.AspNetCore.Identity.IdentityUser]'.

Notice I'm not even referencing the passed SignInManager object in the constructor (I was but have removed it to simplify). If I remove the SignInManager parameter from the constructor everything works fine.

All the relevant examples I have seen online end up being the case where the SignInManager 's specified user data type in the call to AddIdentity() doesn't match the user data type in the constructor parameter, but that isn't the case in my code.

Reading articles and example code for this makes it seem like this should be a simple task. My constructor's other dependency injected parameters are working just fine except that I have the same issue if I try to inject RoleManager (except with a slightly different exception message).

Answer 1

While you have added Identity, you haven't configured any data stores. From the docs you should be doing something like this:

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

If you are using ASP.Net Core 2.1 however, use the newer version:

services.AddDefaultIdentity<IdentityUser>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

Answer 2

User below if you are using asp.net core 3.18 version

services.AddDefaultIdentity<IdentityUser>()
         .AddEntityFrameworkStores<ApplicationDbContext>();