实体类型“IdentityUserRole<string>”需要定义主键

问：

我有以下代码：

using MyBlazorApp.Server.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;

namespace MyBlazorApp.Server.Data
{
    public class ApplicationDbContext : IdentityDbContext<ApplicationUser, IdentityRole<Guid>, Guid>
    {
        public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
            : base(options)
        {
        }        

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<ApplicationUser>()
                .Property(e => e.firstName)
                .HasMaxLength(250);

            modelBuilder.Entity<ApplicationUser>()
                .Property(e => e.lastName)
                .HasMaxLength(250);

            modelBuilder.Entity<ApplicationUser>()
                .Property(e => e.isLdapLogin);

            modelBuilder.Entity<ApplicationUser>()
                .Property(e => e.isMFAforce);

            modelBuilder.Entity<ApplicationUser>()
                .Property(e => e.apiKey);

            modelBuilder.Entity<ApplicationUser>()
                .Property(e => e.IsEnabled);

            //Seeding a  'Administrator' role to AspNetRoles table
            var arId = "dffc6dd5-b145-41e9-a861-c87ff673e9ca";
            modelBuilder.Entity<IdentityRole>().HasData(
                new IdentityRole
                {
                    Id = arId,
                    Name = "Admins",
                    NormalizedName = "ADMINS".ToUpper(),
                    ConcurrencyStamp = arId
                }
            ); ;
            var urId = "f8a527ac-d7f6-4d9d-aca6-46b2261b042b";
            modelBuilder.Entity<IdentityRole>().HasData(
                new IdentityRole
                {
                    Id = urId,
                    Name = "Users",
                    NormalizedName = "USERS".ToUpper(),
                    ConcurrencyStamp = urId
                }
            ); ;

            //a hasher to hash the password before seeding the user to the db
            var hasher = new PasswordHasher<IdentityUser>();

            //Seeding the Admin User to AspNetUsers table
            modelBuilder.Entity<ApplicationUser>().HasData(
                new ApplicationUser
                {
                    Id = new Guid("6fbfb682-568c-4f5b-a298-85937ca4f7f3"), // primary key
                    UserName = "super.admin",
                    NormalizedUserName = "SUPER.ADMIN",
                    PasswordHash = hasher.HashPassword(null, "7ugVUczrm7"),
                    firstName = "Super",
                    lastName = "Admin",
                    Email = "[email protected]",
                    NormalizedEmail = "[email protected]",
                    EmailConfirmed = true,
                    isMFAforce = 0,
                    isLdapLogin = 0
                }
            );

            List<IdentityUserRole<string>> UserRoles = new List<IdentityUserRole<string>>();
            UserRoles.Add(new IdentityUserRole<string>
            {
                RoleId = "dffc6dd5-b145-41e9-a861-c87ff673e9ca",
                UserId = "6fbfb682-568c-4f5b-a298-85937ca4f7f3"
            });
            modelBuilder.Entity<IdentityUserRole<string>>().HasData(UserRoles);
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            base.OnConfiguring(optionsBuilder);
        }

    }
}

当我点击命令时，出现以下错误：实体类型“IdentityUserRole”需要定义主键。dotnet ef migrations add IntitialMigration

我已经找到了我必须使用base的最受欢迎的解决方案。OnModelCreating（modelBuilder）;。但正如你在我的代码中看到的那样，我已经使用了它。

我希望有人知道为什么会抛出这个错误。