Can't Find User By ID

Question

I am trying to create a "User Service" class where I Expose only the methods that would need to go through this. One of this methods is FindById. Here is my code:

using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;
using Microsoft.Owin.Security.DataProtection;

public interface IUserService : IDisposable
{
    Task<CustomUser> FindByIdAsync(string userId);
    ICustomUser FindById(string userId);
}

public class UserService : UserManager<CustomUser>, IUserService
{
    public UserService(IUserStore<CustomUser> store, IDataProtectionProvider dataProvider)
        : base(store)
    {
        UserValidator = new UserValidator<CustomUser>(this)
        {
            AllowOnlyAlphanumericUserNames = false,
            RequireUniqueEmail = true
        };

        PasswordValidator = new PasswordValidator
        {
            RequiredLength = 8,
            RequireNonLetterOrDigit = true,
            RequireDigit = true,
            RequireLowercase = true,
            RequireUppercase = true,
        };

        UserLockoutEnabledByDefault = true;
        DefaultAccountLockoutTimeSpan = TimeSpan.FromMinutes(1);
        MaxFailedAccessAttemptsBeforeLockout = 5;

        var dataProtectionProvider = dataProvider;
        if (dataProtectionProvider != null)
        {
            UserTokenProvider =
                new DataProtectorTokenProvider<CustomUser>(dataProtectionProvider.Create("ASP.NET Identity"));
        }
    }

    public new async Task<ICustomUser> FindByIdAsync(string userId)
    {
        return await base.FindByIdAsync(userId);
    }

    public ICustomUser FindById(string userId)
    {
        return base.FindById(userId);
    }
}

The FindByIdAsync method works fine, however the FindById method won't even compile. My autocomplete suggests that the method is there, but when I type it out, it becomes red and says:

Microsoft.AspNet.Identity.UserManager does not contain a definition for FindById

What am I doing wrong?

EDIT:

FindById comes from UserManagerExtensions (see https://msdn.microsoft.com/en-us/library/dn497471(v=vs.108).aspx ). Does this mean that I have to extend the extensions class somehow? All I am really trying to do is allow the use of this method via my interface which is IUserService, but adding a reference there it forces me to implement a method, which I tried to do with little success as you can see above

Answer 1

You can't call an extension method for base

The reason for that seems to be that you can't pass base as a parameter, and that what an extension method is.

You can call the method in a static context like this, instead of as an extension.

public ICustomUser FindById(string userId)
{
    return UserManagerExtentions.FindById(this, userId);
}