Identity Core 2 IdentityRole是否缺少用户定义?

我是否遗漏了什么,或者用户的定义是否已从中删除 IdentityRole 在Identity Core 2中?

我正在使用asp。net core 2和我需要计算每个角色的用户数。这在Core 1中运行良好,使用了以下标准代码

public class ApplicationRoleController : Controller
{
    private readonly RoleManager<ApplicationRole> roleManager;    
    public ApplicationRoleController(RoleManager<ApplicationRole> roleManager)
    {
        this.roleManager = roleManager;
    }

    [HttpGet]
    public IActionResult Index()
    {
        List<ApplicationRoleListViewModel> model = new List<ApplicationRoleListViewModel>();
        model = roleManager.Roles.Select(r => new
        {
            RoleName = r.Name,
            Id = r.Id,
            Description = r.Description,
            NumberOfUsers = r.Users.Count
        }).ToList()
        .Select(r => new ApplicationRoleListViewModel
        {
            RoleName = r.RoleName,
            Id = r.Id,
            Description = r.Description,
            NumberOfUsers = r.NumberOfUsers
        }).ToList();

        return View(model);
    }

在我使用Core 2的应用程序中 NumberOfUsers = r.Users.Count ,其中r是从类派生的 ApplicationRole 错误为“ApplicationRole不包含用户定义” 应用程序角色 继承自 识别符 .

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using System;

public class ApplicationRole : IdentityRole
{
    public string Description { get; set; }
    public DateTime CreatedDate { get; set; }
    public string IPAddress { get; set; }
}