无法获得具有角色的用户 Asp.net MVC5 身份 2.2.1 依赖注入

Question

大家好！

在阅读了my previous question 的MRebati 提示后，我搜索并了解了blog 的重要性，不将统一和OWIN 混合以及如何依赖注入ASP.net 身份。

所以首先我不想被标记为问同样的问题，即使我是，但现在我的代码与上一个问题相比发生了一些变化。

无论如何，现在我收到了不同的错误消息：

对象引用未设置为对象的实例。

这意味着我在调用我的自定义用户管理器时仍然为空。

我想要的结果是获得我的所有用户及其接受角色的列表：

XXXXXX ------ 管理员

YYYYYY ------ 经理

关于我的项目的信息：

MVC：5.2.3

身份：2.2.1

实体框架：代码优先 2.2.1

我还尝试在 Unity 中使用依赖注入。

这是我的代码：

控制器：

public ActionResult GetUsersWithRoles(string roleName)
        {

            ViewBag.UsersWithRoles = _userManager.GetUsersInRole(context, roleName);


            return View(ViewBag.UsersWithRoles);
        }

我在 IdentityConfig.cs 中的自定义用户管理器：

    public class ApplicationUserManager : UserManager<ApplicationUser>
        {
            public ApplicationUserManager(IUserStore<ApplicationUser> store)
                : base(store)
            {
/// the create part which is moved from the default /// 
          public IQueryable<ApplicationUser> GetUsersInRole(ApplicationDbContext context, string roleName)
                {
                    if (context !=null && roleName !=null)
                    {
                        var roles = context.Roles.Where(r => r.Name == roleName);
                        if (roles.Any())
                        {
                            var roleId = roles.First().Id;
                            return from user in context.Users
                                   where user.Roles.Any(r => r.RoleId == roleId)
                                   select user;
                        }
                    }

                return null;
            }

最后是我的观点：

@using (Html.BeginForm("GetUsersWithRoles", "Roles"))
{
    @Html.AntiForgeryToken()
    @Html.ValidationSummary(true)

    <h3>Roles for this user </h3>

    foreach (IQueryables in ViewBag.UsersWithRoles)
    {
        <tr>

            <td>@s</td>
        </tr>
    }


}

这是我的 unityConfig.cs

using System;
using Microsoft.Practices.Unity;
using Microsoft.Practices.Unity.Configuration;
using eCommerce.DAL.Repositories;
using eCommerce.Model;
using eCommerce.Contracts.Repositories;
using eCommerce.WebUI.Controllers;
using eCommerce.WebUI.Models;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;

namespace eCommerce.WebUI.App_Start
{

    public class UnityConfig
    {
        #region Unity Container
        private static Lazy<IUnityContainer> container = new Lazy<IUnityContainer>(() =>
        {
            var container = new UnityContainer();
            RegisterTypes(container);
            return container;
        });


        public static IUnityContainer GetConfiguredContainer()
        {
            return container.Value;
        }
        #endregion


        public static void RegisterTypes(IUnityContainer container)
        {

            container.RegisterType<IRepositoryBase<Customer>, CustomerRepository>();
            container.RegisterType<IRepositoryBase<Product>, ProductRepository>();
            container.RegisterType<IRepositoryBase<Basket>, BasketRepository>();
            container.RegisterType<IRepositoryBase<Voucher>, VoucherRepository>();
            container.RegisterType<IRepositoryBase<VoucherType>, VoucherTypeRepository>();
            container.RegisterType<IRepositoryBase<BasketVoucher>, BasketVoucherRepository>();
            container.RegisterType<IRepositoryBase<BasketItem>, BasketItemsRepository>();
            //container.RegisterType<AccountController>(new InjectionConstructor());
            container.RegisterType<ApplicationDbContext>(new PerRequestLifetimeManager());
            container.RegisterType<ApplicationUserManager>();
            container.RegisterType <IUserStore<ApplicationUser>, UserStore<ApplicationUser>>(new InjectionConstructor(typeof(ApplicationDbContext)));


        }
    }
}

这是 RolesController.cs 的构造函数：

 private ApplicationDbContext context;
        private ApplicationUserManager _userManager;

        public RolesController(ApplicationDbContext context, ApplicationUserManager _userManager)
        {

            this.context = context;
            this._userManager = _userManager;
        }

这是我的 startup.cs： 一个

ssembly: OwinStartupAttribute(typeof(eCommerce.WebUI.Startup))]
namespace eCommerce.WebUI
{
    public partial class Startup
    {
        internal static IDataProtectionProvider DataProtectionProvider { get; private set; }

        public void Configuration(IAppBuilder app)
        {
            ConfigureAuth(app);
            //app.CreatePerOwinContext(ApplicationDbContext.Create);
            //app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);

            app.CreatePerOwinContext(() => DependencyResolver.Current.GetService<ApplicationUserManager>()); // <-
            DataProtectionProvider = app.GetDataProtectionProvider();

        }



    }
}

这是我的 Global.asax：

 public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);

            AreaRegistration.RegisterAllAreas();

            var context = new ApplicationDbContext();
            if (!context.Users.Any(user => user.UserName == "Email@hotmail.com"))
            {
                var userStore = new UserStore<ApplicationUser>(context);
                var userManager = new UserManager<ApplicationUser>(userStore);
                var applicationUser = new ApplicationUser() { UserName = "Email@hotmail.com" };
                userManager.Create(applicationUser, "Password");

                var roleStore = new RoleStore<IdentityRole>(context);
                var roleManager = new RoleManager<IdentityRole>(roleStore);
                roleManager.Create(new IdentityRole("Admin"));

                userManager.AddToRole(applicationUser.Id, "Admin");

            }
        }

    }

从我的角色控制器创建方法：

[HttpPost]
        public ActionResult Create(FormCollection collection)
        {
            try
            {
                context.Roles.Add(new IdentityRole
                {
                    Name = collection["RoleName"]
                });
                context.SaveChanges();
                ViewBag.ResultMessage = "Role created successfully !";
                return RedirectToAction("Index");
            }
            catch
            {
                return View();
            }
        }

感谢您的宝贵时间。

Answer 1

最好在UserManager 中保留对 DbContext 的引用：

public class ApplicationUserManager : UserManager<ApplicationUser>
{
    private readonly ApplicationDbContext context;

    public ApplicationUserManager(ApplicationDbContext context, /*... other parameters*/) : base(store)
    {
        this.context = context;
        //... other configuration bits
    }

    public IEnumerable<ApplicationUser> GetUsersInRole(string roleName)
    {
        if (String.IsNullOrWhiteSpace(roleName))
        {
            throw new ArgumentNullException(nameof(roleName));
        }

        var role = context.Roles.FirstOrDefault(r => r.Name == roleName);

        if (role == null)
        {
            throw new Exception($"Role with this name not found: {roleName}");
        }

        var users = context.Users.Where(u => u.Roles.Any(r => r.RoleId == role.Id)).ToList();

        return users;
    }

    // the rest of User manager methods
}

在您的控制器中避免使用ViewBag - 这不是一个好习惯。此外，正如已经提到的，永远不要将IQueryable 传递给您的视图。粗略地说IQueryable 是一个SQL 查询，但IEnumerable 是一个对象的集合。 View 只需要知道对象。所以你的控制器看起来像这样：

public class UsersWithRoleController : Controller
{
    private readonly ApplicationUserManager userManager;

    public UsersWithRoleController(ApplicationUserManager userManager)
    {
        this.userManager = userManager;
    }

    public ActionResult GetUsersWithRoles(string roleName)
    {
        var users = userManager.GetUsersInRole(roleName);

        var viewModel = new GetUsersWithRolesViewModel()
        {
            RoleName = roleName,
            Users = users,
        };

        return View(viewModel);
    }

}

public class GetUsersWithRolesViewModel
{
    public String RoleName { get; set; }
    public IEnumerable<ApplicationUser> Users { get; set; }
}

视图将是：

@model IoCIdentity.Controllers.GetUsersWithRolesViewModel

@{
    ViewBag.Title = "title";
}

<h2>List of users in role @Model.RoleName</h2>

<ul>
    @foreach (var user in @Model.Users)
    {
        <li>@user.UserName</li>
    }
</ul>

您可以在我的github 中获取完整示例。虽然我没有正确测试它——我的数据库现在坏了——（