C# 实体类型IdentityRole不是当前上下文的一部分

我目前正试图将角色添加到我的应用程序中，我收到了一个错误“EntityTypeIdentityRole不是当前上下文的一部分”。我以前也有同样的错误，除了AppRole，但我通过在AppIdentityDdbContext类中包含IdentityDdbContext之后的所有参数解决了这个问题，但是我无法修复这个问题，谢谢您的帮助

这是我得到错误信息的线路

ClaimsIdentity ident = await UserManager.CreateIdentityAsync(user,DefaultAuthenticationTypes.ApplicationCookie);

DbContext类

 public class AppIdentityDbContext : IdentityDbContext<User, AppRole, string, IdentityUserLogin, IdentityUserRole, IdentityUserClaim>
    {
        public AppIdentityDbContext() : base("ProGP_Db") { }

        static AppIdentityDbContext()
        {
            Database.SetInitializer<AppIdentityDbContext>(new IdentityDbInit());
        }
        public static AppIdentityDbContext Create()
        {
            return new AppIdentityDbContext();
        }
    }
    public class IdentityDbInit
    : DropCreateDatabaseIfModelChanges<AppIdentityDbContext>
    {
        protected override void Seed(AppIdentityDbContext context)
        {
            PerformInitialSetup(context);
            base.Seed(context);
        }
        public void PerformInitialSetup(AppIdentityDbContext context)
        {
            // initial configuration will go here
        }
    }

---

问题在于我显式声明了IdentityRole的UserStore，我创建了另一个从UserStore扩展的类，解决了这个问题

public class AppUserStore<TUser> : UserStore<TUser, Role, string, IdentityUserLogin, IdentityUserRole, IdentityUserClaim>, IUserStore<TUser>, IUserStore<TUser, string>, IDisposable where TUser : Microsoft.AspNet.Identity.EntityFramework.IdentityUser {

public AppUserStore(DbContext context) :base(context) {}     }

公共类AppUserStore:UserStore、IUserStore、IUserStore、IDisposable其中TUser:Microsoft.AspNet.Identity.EntityFramework.IdentityUser{
公共AppUserStore（DbContext上下文）：基（上下文）{}

public class AppRoleManager : RoleManager<AppRole>,IDisposable
{
    public AppRoleManager(RoleStore<AppRole> store):base(store)
    { }


    public static AppRoleManager Create(IdentityFactoryOptions<AppRoleManager> options, IOwinContext context)
    {
        //AppIdentityDbContext db = context.Get<AppIdentityDbContext>();
        //AppRoleManager manager = new AppRoleManager(new RoleStore<AppRole>(db));
        return new AppRoleManager(new RoleStore<AppRole>(context.Get<AppIdentityDbContext>()));

        //return manager;
    }
}

  public class AppRole:IdentityRole
{
    public AppRole():base() { }


    public AppRole(string name) : base (name)
    {
    }
}

public class AppUserStore<TUser> : UserStore<TUser, Role, string, IdentityUserLogin, IdentityUserRole, IdentityUserClaim>, IUserStore<TUser>, IUserStore<TUser, string>, IDisposable where TUser : Microsoft.AspNet.Identity.EntityFramework.IdentityUser {

public AppUserStore(DbContext context) :base(context) {}     }