Seed Roles (RoleManager vs RoleStore)

问题

Through looking at the posts here, I've seen two different ways of creating ASP.NET Identity roles through Entity Framework seeding. One way uses RoleManager and the other uses RoleStore. I was wondering if there is a difference between the two. As using the latter will avoid one less initialization

string[] roles = { "Admin", "Moderator", "User" };

// Create Role through RoleManager

var roleStore = new RoleStore<IdentityRole>(context);
var manager = new RoleManager<IdentityRole>(roleStore);

foreach (string role in roles)
{
    if (!context.Roles.Any(r => r.Name == role))
    {
       manager.Create(new IdentityRole(role));
    }

// Create Role through RoleStore

var roleStore = new RoleStore<IdentityRole>(context);

foreach (string role in roles)
{
    if (!context.Roles.Any(r => r.Name == role))
    {
       roleStore.CreateAsync(new IdentityRole(role));
    }
}

回答1:

In your specific case, using both methods, you achieve the same results.

But, the correct usage would be:

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

string[] roles = { "Admin", "Moderator", "User" };

foreach (string role in roles)
{
     if (!roleManager.RoleExists(role))
     {
           roleManager.Create(new IdentityRole(role));
     }
}

The RoleManager is a wrapper over a RoleStore, so when you are adding roles to the manager, you are actually inserting them in the store, but the difference here is that the RoleManager can implement a custom IIdentityValidator<TRole> role validator.

So, implementing the validator, each time you add a role through the manager, it will first be validated before being added to the store.

来源：https://stackoverflow.com/questions/40183642/seed-roles-rolemanager-vs-rolestore