检查用户是否在 asp.net mvc Identity 中的角色

Question

I'm having an issue seeding my database with users and roles.

The User and the Role are both created (I can see them in the database after the error is thrown).

However, when I try to check if the user is in a role, I get an exception.

My code is:

    public class tbInitializer<T> : DropCreateDatabaseAlways<tbContext>
    {
    protected override void Seed(tbContext context)
    {
        ApplicationDbContext userscontext = new ApplicationDbContext();
        var userStore = new UserStore<ApplicationUser>(userscontext);
        var userManager = new UserManager<ApplicationUser>(userStore);

        var roleStore = new RoleStore<IdentityRole>(userscontext);
        var roleManager = new RoleManager<IdentityRole>(roleStore);


        if(!userscontext.Users.Any(x=> x.UserName=="marktest"))
        {
            var user = new ApplicationUser { UserName = "marktest", Email = "marktest@gmail.com" };
            userManager.Create(user, "Pa$$W0rD!");
        }

        if (!roleManager.RoleExists("Admin"))
        { 
            roleManager.Create(new IdentityRole("Admin"));
        }

        if(!userManager.IsInRole("marktest","Admin"))
        { 
            userManager.AddToRole("marktest","Admin");
        }

However, on the line:

if(!userManager.IsInRole("marktest","Admin"))

An exception is thrown with the error: UserId not found.

The User and the Role are both in the database when I check after the exception is thrown:

Can anyone see what I'm doing wrong?

Thanks for any help,

Mark

Answer 1

I found out the solution, in case anyone else is having this problem.

The "IsInRole" is expecting a User.Id - not a UserName string - so I changed to:

            if (!userManager.IsInRole(user.Id, "Admin"))
            {
                userManager.AddToRole(user.Id, "Admin");
            }

So the working code becomes:

    ApplicationDbContext userscontext = new ApplicationDbContext();
    var userStore = new UserStore<ApplicationUser>(userscontext);
    var userManager = new UserManager<ApplicationUser>(userStore);

    var roleStore = new RoleStore<IdentityRole>(userscontext);
    var roleManager = new RoleManager<IdentityRole>(roleStore);

    // Create Role
    if (!roleManager.RoleExists("Admin"))
    { 
        roleManager.Create(new IdentityRole("Admin"));
    }

    if(!userscontext.Users.Any(x=> x.UserName=="marktest"))
    {
        // Create User
        var user = new ApplicationUser { UserName = "marktest", Email = "marktest@gmail.com" };
        userManager.Create(user, "Pa$$W0rD!");

        // Add User To Role
        if (!userManager.IsInRole(user.Id, "Admin"))
            {
                userManager.AddToRole(user.Id, "Admin");
            }


    }

I hope that helps,

Mark

Answer 2

生活中最简单的事；

bool isAdmin= User.IsInRole("admin") 

Answer 3

To add to Mark's post above in its still pretty much the same in .NET Core 3.1 Identity only difference with the async method IsInRoleAsync you have to pass in the IdentityUser type object:

var userInRole = await _userManager.IsInRoleAsync(user, role);

Then you can apply your logic afterwards (in my case I was doing two things, first checking the role actually exists and then checking if the user isn't already assigned to that role).