Asp.Net core MVC6 How to initially add roles in Identity 3

问题

I've looked for this in Stackoverflow and so far it appears there are plenty of questions on adding roles in Identity 1 & 2 but its different in Identity 3.

I want to seed roles in the database. I have just two. I intended to use _roleManager which I have injected into the class. Thats fine. My problem is.. there doesnt appear to be any method to actually add a role.. Using CreateAsync is for adding the user to the role.. how do you code to add a role using "_userManager" or do you have to do it another way?

回答1:

EDIT

Identity

In Identity RoleManager is for creating roles and UserManager is for adding users to roles. This is an example to point you in the right direction. The code below is for creating a new role Administrator

if (!roleManager.RoleExists("Administrator"))
            {
                MyIdentityRole newRole = new MyIdentityRole("Administrator", "Administrators can do something with data");
                roleManager.Create(newRole);
            }  

EDIT

Further, this is for adding a user to a role and this also an example:

 \\assuming you test if the user has been assigned to the role "Administrator" before adding them to that role

 if(RoleAdministrator == true){
           userManager.AddToRole(User.Id, "Administrator");
       }

回答2:

public class SeedData
{
    private const string _adminRoleName = "admin";
    private string _adminEmail = "admin@demo.com";
    private string _adminPassword = "P@ssw0rd!PK";

    private string[] _roles = new string[] { _adminRoleName, "supervisor" };

    private readonly RoleManager<IdentityRole<Guid>> _roleManager;
    private readonly UserManager<ApplicationUser> _userManager;

    public  static async Task Run(IServiceProvider serviceProvider)
    {
        using (var serviceScope =serviceProvider
                                 .GetRequiredService<IServiceScopeFactory>()
                                 .CreateScope())
        {
            var instance = serviceScope.ServiceProvider.GetService<SeedData>();
            await instance.Initialize();

            var context = serviceScope.ServiceProvider.GetService<AppDbContext>();
            if (!context.Products.Any())
            {
               // Seed Other entities Here
            }

            await context.SaveChangesAsync();
        }
    }

    public SeedData(UserManager<ApplicationUser> userManager, 
                                  RoleManager<IdentityRole<Guid>> roleManager)
    {
        _roleManager = roleManager;
        _userManager = userManager;
    }

    public async Task Initialize()
    {
        foreach (var role in _roles)
        {
            if (!await _roleManager.RoleExistsAsync(role))
            {
                await _roleManager.CreateAsync(new IdentityRole<Guid>(role));
            }
        }

        var adminUsers = await _userManager.GetUsersInRoleAsync(_adminRoleName);
        if (!adminUsers.Any())
        {
            var adminUser = new ApplicationUser()
            {
                Id = Guid.NewGuid(),
                Email = _adminEmail,
                UserName = _adminEmail
            };

            var result = await _userManager.CreateAsync(adminUser, _adminPassword);
            if(result.Success)
            {
               await _userManager.AddToRoleAsync(adminUser, _adminRoleName);
            }
       }         
   }
}

In your Startup.cs

public static void Main(string[] args)
{
     var host = BuildWebHost(args);

     using (var scope = host.Services.CreateScope())
     {
         var services = scope.ServiceProvider;
         try
         {
              SeedData.Run(services).Wait();
         }
         catch (Exception ex)
         {
             var logger = services.GetRequiredService<ILogger<Program>>();
             logger.LogError(ex, "Error while seeding database.");
         }
     }

      host.Run();
  }

Might be helpful to someone :)

来源：https://stackoverflow.com/questions/36807591/asp-net-core-mvc6-how-to-initially-add-roles-in-identity-3