Missed User 属性，用于计算 asp.net 核心身份中的用户/角色数

Question

场景：

我有一个使用身份验证的 Asp.net 核心程序。

目标：

我想获取具有如下特定角色的用户数量：

    private readonly UserManager<ApplicationUser> _userManager;
    private readonly RoleManager<ApplicationRole> _roleManager;

    public RoleController(UserManager<ApplicationUser> userManager, RoleManager<ApplicationRole> roleManager)
    {
        _userManager = userManager;
        _roleManager = roleManager;
    }

    public IActionResult Index()
    {
        List<roleListViewModel> model = new List<roleListViewModel>();
        model = _roleManager.Roles.Select(r => new roleListViewModel
        {
            id = r.Id,
            Name = r.Name,
            Description = r.Description,
            NumberOfUsers = r.User.count

        }).ToList();

        return View(model);
    }

问题是：

我在NumberOfUsers = r.User.count 行中找不到用户。

角色模型：

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

角色视图模型：

public class roleListViewModel
{
    public string id { get; set; }

    [Required(ErrorMessage = "Name can not empty")]
    [Display(Name ="Name")]
    public string Name { get; set; }

    public int NumberOfUsers { get; set; }

    [Required(ErrorMessage = "Description can not empty")]
    [Display(Name = "Description")]
    public string Description { get; set; }
}

查看索引：

            @foreach (var item in Model)
            {
                <tr>
                    <td>@item.Name</td>
                    <td>@item.Description</td>
                    <td>@item.NumberOfUsers</td>
                </tr>
            }

提前致谢

Answer 1

这适用于所有角色。

var allUserRoles = _identityDb.UserRoles.ToList();
model = _roleManager.Roles.Select(r => new roleListViewModel
{
    Id = r.Id,
    Name = r.Name,
    Description = r.Description,
    NumberOfUsers = allUserRoles.Count(ur => ur.RoleId == r.Id)
}).ToList();

特殊角色

var usersBySpecialRole = _userManager.GetUsersInRoleAsync("myRole").Result;