无法解析类型“Microsoft.AspNetCore.Identity.RoleManager”的服务

Question

我在 asp.net 核心项目

中编写用于向用户添加角色的代码

这是我的角色控制器。

public class RolesController : Controller
{
    RoleManager<IdentityRole> _roleManager;
    UserManager<AspNetUsers> _userManager;
    public RolesController(RoleManager<IdentityRole> roleManager, UserManager<AspNetUsers> userManager)
    {
        _roleManager = roleManager;
        _userManager = userManager;
    }
    public IActionResult Index() => View(_roleManager.Roles.ToList());

    public IActionResult Create() => View();
    [HttpPost]
    public async Task<IActionResult> Create(string name)
    {
        if (!string.IsNullOrEmpty(name))
        {
            IdentityResult result = await _roleManager.CreateAsync(new IdentityRole(name));
            if (result.Succeeded)
            {
                return RedirectToAction("Index");
            }
            else
            {
                foreach (var error in result.Errors)
                {
                    ModelState.AddModelError(string.Empty, error.Description);
                }
            }
        }
        return View(name);
    }

    [HttpPost]
    public async Task<IActionResult> Delete(string id)
    {
        IdentityRole role = await _roleManager.FindByIdAsync(id);
        if (role != null)
        {
            IdentityResult result = await _roleManager.DeleteAsync(role);
        }
        return RedirectToAction("Index");
    }

    public IActionResult UserList() => View(_userManager.Users.ToList());

    public async Task<IActionResult> Edit(string userId)
    {
        // получаем пользователя
        AspNetUsers user = await _userManager.FindByIdAsync(userId);
        if(user!=null)
        {
            // получем список ролей пользователя
            var userRoles = await _userManager.GetRolesAsync(user);
            var allRoles = _roleManager.Roles.ToList();
            ChangeRoleViewModel model = new ChangeRoleViewModel
            {
                UserId = user.Id,
                UserEmail = user.Email,
                UserRoles = userRoles,
                AllRoles = allRoles
            };
            return View(model);
        }

        return NotFound();
    }
    [HttpPost]
    public async Task<IActionResult> Edit(string userId, List<string> roles)
    {

        AspNetUsers user = await _userManager.FindByIdAsync(userId);
        if(user!=null)
        {

            var userRoles = await _userManager.GetRolesAsync(user);

            var allRoles = _roleManager.Roles.ToList();

            var addedRoles = roles.Except(userRoles);

            var removedRoles = userRoles.Except(roles);

            await _userManager.AddToRolesAsync(user, addedRoles);

            await _userManager.RemoveFromRolesAsync(user, removedRoles);

            return RedirectToAction("UserList");
        }

        return NotFound();
    }
}

但是当我运行应用程序并转到角色控制器时。我得到这个错误

An unhandled exception occurred while processing the request. InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.RoleManager`1[Microsoft.AspNetCore.Identity.IdentityRole]' while attempting to activate 'VchasnoCrm.Controllers.RolesController'. Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, bool isDefaultParameterRequired)

我该如何解决这个问题？

Answer 1

因此，为了使其有效，我需要将此行添加到 Startup.cs 文件

services.AddIdentity<IdentityUser, IdentityRole>() .AddEntityFrameworkStores<ApplicationDbContext>();

然后像这样更改我的角色控制器

public class RolesController : Controller
{
    RoleManager<IdentityRole> _roleManager;
    UserManager<IdentityUser> _userManager;
    public RolesController(RoleManager<IdentityRole> roleManager, UserManager<IdentityUser> userManager)
    {
        _roleManager = roleManager;
        _userManager = userManager;
    }
    public IActionResult Index() => View(_roleManager.Roles.ToList());

    public IActionResult Create() => View();
    [HttpPost]
    public async Task<IActionResult> Create(string name)
    {
        if (!string.IsNullOrEmpty(name))
        {
            IdentityResult result = await _roleManager.CreateAsync(new IdentityRole(name));
            if (result.Succeeded)
            {
                return RedirectToAction("Index");
            }
            else
            {
                foreach (var error in result.Errors)
                {
                    ModelState.AddModelError(string.Empty, error.Description);
                }
            }
        }
        return View(name);
    }

    [HttpPost]
    public async Task<IActionResult> Delete(string id)
    {
        IdentityRole role = await _roleManager.FindByIdAsync(id);
        if (role != null)
        {
            IdentityResult result = await _roleManager.DeleteAsync(role);
        }
        return RedirectToAction("Index");
    }

    public IActionResult UserList() => View(_userManager.Users.ToList());

    public async Task<IActionResult> Edit(string userId)
    {
        // получаем пользователя
        IdentityUser user = await _userManager.FindByIdAsync(userId);
        if(user!=null)
        {
            // получем список ролей пользователя
            var userRoles = await _userManager.GetRolesAsync(user);
            var allRoles = _roleManager.Roles.ToList();
            ChangeRoleViewModel model = new ChangeRoleViewModel
            {
                UserId = user.Id,
                UserEmail = user.Email,
                UserRoles = userRoles,
                AllRoles = allRoles
            };
            return View(model);
        }

        return NotFound();
    }
    [HttpPost]
    public async Task<IActionResult> Edit(string userId, List<string> roles)
    {
        // получаем пользователя
        IdentityUser user = await _userManager.FindByIdAsync(userId);
        if(user!=null)
        {
            // получем список ролей пользователя
            var userRoles = await _userManager.GetRolesAsync(user);
            // получаем все роли
            var allRoles = _roleManager.Roles.ToList();
            // получаем список ролей, которые были добавлены
            var addedRoles = roles.Except(userRoles);
            // получаем роли, которые были удалены
            var removedRoles = userRoles.Except(roles);

            await _userManager.AddToRolesAsync(user, addedRoles);

            await _userManager.RemoveFromRolesAsync(user, removedRoles);

            return RedirectToAction("UserList");
        }

        return NotFound();
    }
}

Answer 2

我在使用 .net core 3.0、身份服务器 4 和 angular SPA 默认模板（由 Rider 自动生成的项目）时遇到了类似的问题。

在我的案例中 Startup.cs 包含：

services.AddDefaultIdentity<ApplicationUser().AddEntityFrameworkStores<ApplicationDbContext>();

我必须添加 .AddRoles<IdentityRole>() 并将其更改为：

services.AddDefaultIdentity<ApplicationUser().AddRoles<IdentityRole>().AddEntityFrameworkStores<ApplicationDbContext>();

Answer 3

在 Net Core 3.1 中有两个不同的 ASP.NET Core Identity 重载，第一个版本名为 DefaultIdentity，您没有机会同时设置 User 和 Roles，因此语法看起来像

services.AddDefaultIdentity<IdentityUser>(options => ...

身份的第二个版本使用用户和角色，看起来像

services.AddIdentity<IdentityUser, IdentityRole>(options => ...

这是不同版本的身份，第一个包含 IdentityUI，第二个不包含 IdentityUI。但是，如果您将角色服务添加为

，您可以将角色包含到第一个版本中

services.AddDefaultIdentity<IdentityUser>(options =>...).AddRoles<IdentityRole>()...

如果您已将角色服务包含到您的服务集中，您可以将角色注入到 Configure 方法中，如

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, DbContextOptions<ApplicationDbContext> identityDbContextOptions, UserManager<IdentityUser> userManager, RoleManager<IdentityRole> roleManager)

如果您注入

，通常会出现此错误消息

RoleManager<IdentityRole> roleManager

在项目的任何地方，无需添加 IdentityRole 服务（通过第一种或第二种方式）。

Answer 4

在startup.cs文件中，您必须在其中一项服务中添加.addRoles<IdentityRole>()：

services.AddDefaultIdentity<Usuarios>(options => options.SignIn.RequireConfirmedAccount = true)
  .AddRoles<IdentityRole>() //Line that can help you
  .AddEntityFrameworkStores<ApplicationDbContext>();

Answer 5

在Net Core 3.1中，您需要为身份服务配置辅助函数。为此，您需要创建一个新实例 Microsoft.AspNetCore.Identity.IdentityBuilder.To activate RoleManager service -

转到您的 startup.cs 文件。

在我的例子中，语法看起来像 -

var builder = services.AddIdentityCore<AppUser>();
      builder.AddRoles<IdentityRole>()
             .AddEntityFrameworkStores<AppIdentityDbContext>();

无法解析类型“Microsoft.AspNetCore.Identity.RoleManager”的服务

Unable to resolve service for type 'Microsoft.AspNetCore.Identity.RoleManager`

.net

c#

asp.net

asp.net-identity