在asp.net核心的dbcontext中播种用户和角色：循环依赖问题

Question

I am injecting UserManager and RoleManager in the dbcontext file to use them for adding some users and roles when the database is first created. When I run the update-database command, I receive the following error:

A circular dependency was detected for the service of type 'App.Models.AppDbContext'. App.Models.AppDbContext -> Microsoft.AspNetCore.Identity.UserManager -> Microsoft.AspNetCore.Identity.IUserStore

Below is the dbcontext :

public class AppDbContext : IdentityDbContext
{
    private readonly UserManager<ApplicationUser> _userManager;
    private readonly RoleManager<IdentityRole> _roleManager;

    public AppDbContext(
        DbContextOptions<SynergyDbContext> options,
        UserManager<ApplicationUser> userManager,
        RoleManager<IdentityRole> roleManager
        ) : base(options) {

        _userManager = userManager;
        _roleManager = roleManager;
    }

    modelBuilder.Entity<IdentityRole>().HasData(new IdentityRole { Name = "Admin", NormalizedName = "Admin".ToUpper() });

     ApplicationUser user = new ApplicationUser
     {
         //implementation details
     };

     IdentityResult result = _userManager.CreateAsync(user, "password").Result;
     if (result.Succeeded) _userManager.AddToRoleAsync(user, "Admin").Wait();

     base.OnModelCreating(modelBuilder);
 }

Any ideas? Should I create the users with HasData method?

Answer 1

Your AppDbContext is injected with dependency UserManager which is injected with dependency UserStore which is needed to be injected with dependency DbContext . Therefore you get circular dependency problem.

Solution is to create your users outside of DbContext , so you don't inject those services into DbContext .