public class ApplicationUserLogin : IdentityUserLogin<int> { }
public class ApplicationUserRole : IdentityUserRole<int> { }
public class ApplicationUserClaim : IdentityUserClaim<int> { }
 
public sealed class ApplicationRole : IdentityRole<int>
{
  public ApplicationRole() { }
  public ApplicationRole(string name) { Name = name; }
}
 
public class ApplicationUserStore : UserStore<ApplicationUser,ApplicationRole,ApplicationDbContext,int>
{
  public ApplicationUserStore(ApplicationDbContext context) : base(context) { }
}
 
public class ApplicationRoleStore : RoleStore<ApplicationRole,int>
{
  public ApplicationRoleStore(ApplicationDbContext context) : base(context) { }
}
 
public class ApplicationUser : IdentityUser<int>
{
}
 
public sealed class ApplicationDbContext : IdentityDbContext<ApplicationUser,int>
{
  private static bool _created;
 
  public ApplicationDbContext()
  {
    // Create the database and schema if it doesn't exist
    if (!_created) {
      Database.AsRelational().Create();
      Database.AsRelational().CreateTables();
      _created = true;
    }
  }
}

这可以编译好，但是会抛出一个运行时错误：

System.TypeLoadException

GenericArguments[0],‘TeacherPlanner.Models.ApplicationUser’,on ‘Microsoft.AspNet.Identity.EntityFramework.UserStore`4[TUser,TRole,TContext,TKey]’ violates the constraint of type parameter ‘TUser’.

UserStore的签名是：

public class UserStore<TUser,TKey>
where TUser : Microsoft.AspNet.Identity.EntityFramework.IdentityUser<TKey>
where TRole : Microsoft.AspNet.Identity.EntityFramework.IdentityRole<TKey>
where TContext : Microsoft.Data.Entity.DbContext
where TKey : System.IEquatable<TKey>

ApplicationUser正是一个IdentityUser< int>。这不是它在寻找什么吗？