.net core 3.0更改默认身份认证的的表。

    public class ApplicationDbContext : IdentityDbContext<WebUser, WebRole, Guid, WebUserClaim, WebUserRole, WebUserLogin, WebRoleClaim, WebUserToken>
    {
        public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
            : base(options)
        {
        }

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

            builder.Entity<WebUser>().ToTable("WebUsers");
            builder.Entity<WebRole>().ToTable("WebRoles");
            builder.Entity<WebRoleClaim>().ToTable("WebRoleClaims");
            builder.Entity<WebUserRole>().ToTable("WebUserRoles");
            builder.Entity<WebUserLogin>().ToTable("WebUserLogins");
            builder.Entity<WebRoleClaim>().ToTable("WebRoleClaims");
            builder.Entity<WebUserToken>().ToTable("WebUserTokens");
        }
    }

实体：

    public class WebUser : IdentityUser<Guid>
    {
        public string NickName { get; set; }
    }

依赖注入。        
    services.AddIdentity<WebUser, WebRole>(options => options.SignIn.RequireConfirmedAccount = true)
                .AddEntityFrameworkStores<ApplicationDbContext>();

别忘了cshtml中：

@inject SignInManager<WebUser> SignInManager
@inject UserManager<WebUser> UserManager