Change User Id type to int in ASP.NET Identity in VS2015

1. IdentityModels.cs change to this:

   // New derived classes
   public class UserRole : IdentityUserRole<int>
   {
   }
   
   public class UserClaim : IdentityUserClaim<int>
   {
   }
   
   public class UserLogin : IdentityUserLogin<int>
   {
   }
   
   public class Role : IdentityRole<int, UserRole>
   {
       public Role() { }
       public Role(string name) { Name = name; }
   }
   
   public class UserStore : UserStore<ApplicationUser, Role, int,
       UserLogin, UserRole, UserClaim>
   {
       public UserStore(ApplicationDbContext context): base(context)
       {
       }
   }
   
   public class RoleStore : RoleStore<Role, int, UserRole>
   {
       public RoleStore(ApplicationDbContext context): base(context)
       {
       }
   }
   
   // You can add profile data for the user by adding more properties to your ApplicationUser class, please visit http://go.microsoft.com/fwlink/?LinkID=317594 to learn more.
   public class ApplicationUser : IdentityUser<int, UserLogin, UserRole, UserClaim>
   {
       public DateTime? ActiveUntil;
   
       public async Task<ClaimsIdentity> GenerateUserIdentityAsync(ApplicationUserManager manager)
       {
           // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
           var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
           // Add custom user claims here
           return userIdentity;
       }
   }
   
   public class ApplicationDbContext : IdentityDbContext<ApplicationUser, Role, int,
       UserLogin, UserRole, UserClaim>
   {
       public ApplicationDbContext()
           : base("DefaultConnection")
       {
       }
   
       public static ApplicationDbContext Create()
       {
           return new ApplicationDbContext();
       }
   }
   

2. In `App_Start\IdentityConfig.cs, change the following classes:

   public class ApplicationUserManager : UserManager<ApplicationUser, int>
   {
       public ApplicationUserManager(IUserStore<ApplicationUser, int> store)
           : base(store)
       {
       }
   
       public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, IOwinContext context) 
       {
           var manager = new ApplicationUserManager(new UserStore(context.Get<ApplicationDbContext>()));
           // Configure validation logic for usernames
           manager.UserValidator = new UserValidator<ApplicationUser, int>(manager)
           {
               AllowOnlyAlphanumericUserNames = false,
               RequireUniqueEmail = true
           };
   
           // Configure validation logic for passwords
           manager.PasswordValidator = new PasswordValidator
           {
               RequiredLength = 8,
               // RequireNonLetterOrDigit = true,
               RequireDigit = true,
               RequireLowercase = true,
               RequireUppercase = true,
           };
   
           // Configure user lockout defaults
           manager.UserLockoutEnabledByDefault = true;
           manager.DefaultAccountLockoutTimeSpan = TimeSpan.FromMinutes(5);
           manager.MaxFailedAccessAttemptsBeforeLockout = 5;
   
           // Register two factor authentication providers. This application uses Phone and Emails as a step of receiving a code for verifying the user
           // You can write your own provider and plug it in here.
           manager.RegisterTwoFactorProvider("Phone Code", new PhoneNumberTokenProvider<ApplicationUser, int>
           {
               MessageFormat = "Your security code is {0}"
           });
           manager.RegisterTwoFactorProvider("Email Code", new EmailTokenProvider<ApplicationUser, int>
           {
               Subject = "Security Code",
               BodyFormat = "Your security code is {0}"
           });
           manager.EmailService = new EmailService();
           manager.SmsService = new SmsService();
           var dataProtectionProvider = options.DataProtectionProvider;
           if (dataProtectionProvider != null)
           {
               manager.UserTokenProvider = 
                   new DataProtectorTokenProvider<ApplicationUser, int>(dataProtectionProvider.Create("ASP.NET Identity"));
           }
           return manager;
       }
   }
   
   // Configure the application sign-in manager which is used in this application.
   public class ApplicationSignInManager : SignInManager<ApplicationUser, int>
   {
       public ApplicationSignInManager(ApplicationUserManager userManager, IAuthenticationManager authenticationManager)
           : base(userManager, authenticationManager)
       {
       }
   
       public override Task<ClaimsIdentity> CreateUserIdentityAsync(ApplicationUser user)
       {
           return user.GenerateUserIdentityAsync((ApplicationUserManager)UserManager);
       }
   
       public static ApplicationSignInManager Create(IdentityFactoryOptions<ApplicationSignInManager> options, IOwinContext context)
       {
           return new ApplicationSignInManager(context.GetUserManager<ApplicationUserManager>(), context.Authentication);
       }
   }
   

3. In App_Start\Startup.Auth.cs change OnValidateIdentity property to this:

   OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser, int>(
       validateInterval: TimeSpan.FromMinutes(30),
       regenerateIdentityCallback: (manager, user) => user.GenerateUserIdentityAsync(manager),
       getUserIdCallback: id => id.GetUserId<int>())
   

4. Change ManageController to work with the new pk type:

Replace all entries of User.Identity.GetUserId() to User.Identity.GetUserId<int>()

There might be a couple of string id arguments that need to be changed to int, but that's about it.