如何在 ASP.NET Core 中创建角色并将其分配给用户？

Question

I am using the ASP.NET Core default website template and have the authentication selected as "Individual User Accounts". How can I create roles and assign it to users so that I can use the roles in a controller to filter access?

Answer 1

My comment was deleted because I provided a link to a similar question I answered here . Ergo, I'll answer it more descriptively this time. Here goes.

You could do this easily by creating a CreateRoles method in your startup class. This helps check if the roles are created, and creates the roles if they aren't; on application startup. Like so.

private async Task CreateRoles(IServiceProvider serviceProvider)
    {
        //initializing custom roles 
        var RoleManager = serviceProvider.GetRequiredService<RoleManager<IdentityRole>>();
        var UserManager = serviceProvider.GetRequiredService<UserManager<ApplicationUser>>();
        string[] roleNames = { "Admin", "Manager", "Member" };
        IdentityResult roleResult;

        foreach (var roleName in roleNames)
        {
            var roleExist = await RoleManager.RoleExistsAsync(roleName);
            if (!roleExist)
            {
                //create the roles and seed them to the database: Question 1
                roleResult = await RoleManager.CreateAsync(new IdentityRole(roleName));
            }
        }

        //Here you could create a super user who will maintain the web app
        var poweruser = new ApplicationUser
        {

            UserName = Configuration["AppSettings:UserName"],
            Email = Configuration["AppSettings:UserEmail"],
        };
    //Ensure you have these values in your appsettings.json file
        string userPWD = Configuration["AppSettings:UserPassword"];
        var _user = await UserManager.FindByEmailAsync(Configuration["AppSettings:AdminUserEmail"]);

       if(_user == null)
       {
            var createPowerUser = await UserManager.CreateAsync(poweruser, userPWD);
            if (createPowerUser.Succeeded)
            {
                //here we tie the new user to the role
                await UserManager.AddToRoleAsync(poweruser, "Admin");

            }
       }
    }

and then you could call the CreateRoles(serviceProvider).Wait(); method from the Configure method in the Startup class. ensure you have IServiceProvider as a parameter in the Configure class.

Using role-based authorization in a controller to filter user access: Question 2

You can do this easily, like so.

[Authorize(Roles="Manager")]
public class ManageController : Controller
{
   //....
}

You can also use role-based authorization in the action method like so. Assign multiple roles, if you will

[Authorize(Roles="Admin, Manager")]
public IActionResult Index()
{
/*
 .....
 */ 
}

While this works fine, for a much better practice, you might want to read about using policy based role checks. You can find it on the ASP.NET core documentation here , or this article I wrote about it here

Answer 2

I have created an action in the Accounts controller that calls a function to create the roles and assign the Admin role to the default user. (You should probably remove the default user in production):

    private async Task CreateRolesandUsers()
    {  
        bool x = await _roleManager.RoleExistsAsync("Admin");
        if (!x)
        {
            // first we create Admin rool    
            var role = new IdentityRole();
            role.Name = "Admin";
            await _roleManager.CreateAsync(role);

            //Here we create a Admin super user who will maintain the website                   

            var user = new ApplicationUser();
            user.UserName = "default";
            user.Email = "default@default.com";

            string userPWD = "somepassword";

            IdentityResult chkUser = await _userManager.CreateAsync(user, userPWD);

            //Add default User to Role Admin    
            if (chkUser.Succeeded)
            {
                var result1 = await _userManager.AddToRoleAsync(user, "Admin");
            }
        }

        // creating Creating Manager role     
        x = await _roleManager.RoleExistsAsync("Manager");
        if (!x)
        {
            var role = new IdentityRole();
            role.Name = "Manager";
            await _roleManager.CreateAsync(role);
        }

        // creating Creating Employee role     
        x = await _roleManager.RoleExistsAsync("Employee");
        if (!x)
        {
            var role = new IdentityRole();
            role.Name = "Employee";
            await _roleManager.CreateAsync(role);
        }
  }

After you could create a controller to manage roles for the users.

Answer 3

Temi's answer is nearly correct, but you cannot call an asynchronous function from a non asynchronous function like he is suggesting. What you need to do is make asynchronous calls in a synchronous function like so :

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider serviceProvider)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
            app.UseBrowserLink();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseStaticFiles();

        app.UseIdentity();

        // Add external authentication middleware below. To configure them please see https://go.microsoft.com/fwlink/?LinkID=532715

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });

        CreateRoles(serviceProvider);

    }

    private void CreateRoles(IServiceProvider serviceProvider)
    {

        var roleManager = serviceProvider.GetRequiredService<RoleManager<IdentityRole>>();
        var userManager = serviceProvider.GetRequiredService<UserManager<ApplicationUser>>();
        Task<IdentityResult> roleResult;
        string email = "someone@somewhere.com";

        //Check that there is an Administrator role and create if not
        Task<bool> hasAdminRole = roleManager.RoleExistsAsync("Administrator");
        hasAdminRole.Wait();

        if (!hasAdminRole.Result)
        {
            roleResult = roleManager.CreateAsync(new IdentityRole("Administrator"));
            roleResult.Wait();
        }

        //Check if the admin user exists and create it if not
        //Add to the Administrator role

        Task<ApplicationUser> testUser = userManager.FindByEmailAsync(email);
        testUser.Wait();

        if (testUser.Result == null)
        {
            ApplicationUser administrator = new ApplicationUser();
            administrator.Email = email;
            administrator.UserName = email;

            Task<IdentityResult> newUser = userManager.CreateAsync(administrator, "_AStrongP@ssword!");
            newUser.Wait();

            if (newUser.Result.Succeeded)
            {
                Task<IdentityResult> newUserRole = userManager.AddToRoleAsync(administrator, "Administrator");
                newUserRole.Wait();
            }
        }

    }

The key to this is the use of the Task<> class and forcing the system to wait in a slightly different way in a synchronous way.

Answer 4

I use this (DI):

public class IdentitySeed
{
    private readonly ApplicationDbContext _context;
    private readonly UserManager<ApplicationUser> _userManager;
    private readonly RoleManager<ApplicationRole> _rolesManager;
    private readonly ILogger _logger;

    public IdentitySeed(
        ApplicationDbContext context,
        UserManager<ApplicationUser> userManager,
        RoleManager<ApplicationRole> roleManager,
         ILoggerFactory loggerFactory) {
        _context = context;
        _userManager = userManager;
        _rolesManager = roleManager;
        _logger = loggerFactory.CreateLogger<IdentitySeed>();
    }

    public async Task CreateRoles() {
        if (await _context.Roles.AnyAsync()) {// not waste time
            _logger.LogInformation("Exists Roles.");
            return;
        }
        var adminRole = "Admin";
        var roleNames = new String[] { adminRole, "Manager", "Crew", "Guest", "Designer" };

        foreach (var roleName in roleNames) {
            var role = await _rolesManager.RoleExistsAsync(roleName);
            if (!role) {
                var result = await _rolesManager.CreateAsync(new ApplicationRole { Name = roleName });
                //
                _logger.LogInformation("Create {0}: {1}", roleName, result.Succeeded);
            }
        }
        // administrator
        var user = new ApplicationUser {
            UserName = "Administrator",
            Email = "something@something.com",
            EmailConfirmed = true
        };
        var i = await _userManager.FindByEmailAsync(user.Email);
        if (i == null) {
            var adminUser = await _userManager.CreateAsync(user, "Something*");
            if (adminUser.Succeeded) {
                await _userManager.AddToRoleAsync(user, adminRole);
                //
                _logger.LogInformation("Create {0}", user.UserName);
            }
        }
    }
    //! By: Luis Harvey Triana Vega
}

Answer 5

The following code will work ISA.

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, 
        IServiceProvider serviceProvider)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
            app.UseBrowserLink();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseStaticFiles();

        app.UseIdentity();

        // Add external authentication middleware below. To configure them please see https://go.microsoft.com/fwlink/?LinkID=532715

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });

        CreateRolesAndAdminUser(serviceProvider);
    }

    private static void CreateRolesAndAdminUser(IServiceProvider serviceProvider)
    {
        const string adminRoleName = "Administrator";
        string[] roleNames = { adminRoleName, "Manager", "Member" };

        foreach (string roleName in roleNames)
        {
            CreateRole(serviceProvider, roleName);
        }

        // Get these value from "appsettings.json" file.
        string adminUserEmail = "someone22@somewhere.com";
        string adminPwd = "_AStrongP1@ssword!";
        AddUserToRole(serviceProvider, adminUserEmail, adminPwd, adminRoleName);
    }

    /// <summary>
    /// Create a role if not exists.
    /// </summary>
    /// <param name="serviceProvider">Service Provider</param>
    /// <param name="roleName">Role Name</param>
    private static void CreateRole(IServiceProvider serviceProvider, string roleName)
    {
        var roleManager = serviceProvider.GetRequiredService<RoleManager<IdentityRole>>();

        Task<bool> roleExists = roleManager.RoleExistsAsync(roleName);
        roleExists.Wait();

        if (!roleExists.Result)
        {
            Task<IdentityResult> roleResult = roleManager.CreateAsync(new IdentityRole(roleName));
            roleResult.Wait();
        }
    }

    /// <summary>
    /// Add user to a role if the user exists, otherwise, create the user and adds him to the role.
    /// </summary>
    /// <param name="serviceProvider">Service Provider</param>
    /// <param name="userEmail">User Email</param>
    /// <param name="userPwd">User Password. Used to create the user if not exists.</param>
    /// <param name="roleName">Role Name</param>
    private static void AddUserToRole(IServiceProvider serviceProvider, string userEmail, 
        string userPwd, string roleName)
    {
        var userManager = serviceProvider.GetRequiredService<UserManager<ApplicationUser>>();

        Task<ApplicationUser> checkAppUser = userManager.FindByEmailAsync(userEmail);
        checkAppUser.Wait();

        ApplicationUser appUser = checkAppUser.Result;

        if (checkAppUser.Result == null)
        {
            ApplicationUser newAppUser = new ApplicationUser
            {
                Email = userEmail,
                UserName = userEmail
            };

            Task<IdentityResult> taskCreateAppUser = userManager.CreateAsync(newAppUser, userPwd);
            taskCreateAppUser.Wait();

            if (taskCreateAppUser.Result.Succeeded)
            {
                appUser = newAppUser;
            }
        }

        Task<IdentityResult> newUserRole = userManager.AddToRoleAsync(appUser, roleName);
        newUserRole.Wait();
    }

Answer 6

In addition to Temi Lajumoke's answer, it's worth noting that after creating the required roles and assigning them to specific users in ASP.NET Core 2.1 MVC Web Application , after launching the application, you may encounter a method error, such as registering or managing an account:

InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.UI.Services.IEmailSender' while attempting to activate 'WebApplication.Areas.Identity.Pages.Account.Manage.IndexModel'.

A similar error can be quickly corrected in the ConfigureServices method by adding the AddDefaultUI() method:

services.AddIdentity<IdentityUser, IdentityRole>()
//services.AddDefaultIdentity<IdentityUser>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultUI()
    .AddDefaultTokenProviders();

Check

https://blogs.msdn.microsoft.com/webdev/2018/03/02/aspnetcore-2-1-identity-ui/

and related topic on github:

https://github.com/aspnet/Docs/issues/6784 for more information.

And for assigning role to specific user could be used IdentityUser class instead of ApplicationUser.

Answer 7

In Configure method declare your role manager (Startup)

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, RoleManager<IdentityRole> roleManager)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseHttpsRedirection();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });

        Task.Run(()=>this.CreateRoles(roleManager)).Wait();
    }


    private async Task CreateRoles(RoleManager<IdentityRole> roleManager)
    {
        foreach (string rol in this.Configuration.GetSection("Roles").Get<List<string>>())
        {
            if (!await roleManager.RoleExistsAsync(rol))
            {
                await roleManager.CreateAsync(new IdentityRole(rol));
            }
        }
    }

OPTIONAL - In appsettings.JSON (it depends on you where you wanna get roles from)

{
"Roles": [
"SuperAdmin",
"Admin",
"Employee",
"Customer"
  ]
}

Answer 8

Update in 2020. Here is another way if you prefer.

 IdentityResult res = new IdentityResult();
 var _role = new IdentityRole();
 _role.Name = role.RoleName;
  res = await _roleManager.CreateAsync(_role);
  if (!res.Succeeded)
  {
        foreach (IdentityError er in res.Errors)
        {
             ModelState.AddModelError(string.Empty, er.Description);
         }
         ViewBag.UserMessage = "Error Adding Role";
         return View();
  }
  else
  {
        ViewBag.UserMessage = "Role Added";
        return View();
   }

Answer 9

.net 6 option:

public static class WebApplicationExtensions
{
    public static async Task<WebApplication> CreateRolesAsync(this WebApplication app, IConfiguration configuration)
    {
        using var scope = app.Services.CreateScope();
        var roleManager = (RoleManager<IdentityRole>)scope.ServiceProvider.GetService(typeof(RoleManager<IdentityRole>));
        var roles = configuration.GetSection("Roles").Get<List<string>>();

        foreach (var role in roles)
        {
            if (!await roleManager.RoleExistsAsync(role))
                await roleManager.CreateAsync(new IdentityRole(role));
        }

        return app;
    }
}

In Program.cs add before app.Run()

await app.CreateRolesAsync(builder.Configuration);