the method i Use for creating roles is below, assigning them to users in code is also listed. the below code does be in "configuration.cs" in the migrations folder.
string [] roleNames = { "role1", "role2", "role3" };
var RoleManager = new RoleManager<IdentityRole>(new RoleStore<IdentityRole>(context));
IdentityResult roleResult;
foreach(var roleName in roleNames)
{
if(!RoleManager.RoleExists(roleName))
{
roleResult = RoleManager.Create(new IdentityRole(roleName));
}
}
var UserManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(context));
UserManager.AddToRole("user", "role1");
UserManager.AddToRole("user", "role2");
context.SaveChanges();