在App_Code文件夹中将类组织到命名空间不能按预期工作

namespace MyApp.Models
{
    public class MyClass
    {
        // Your code here
    }
}

using MyApp.Models;

public class MyController : Controller
{
    public ActionResult Index()
    {
        MyClass myClass = new MyClass();
        // Your code here
    }
}

using MyApp.Models;

public class MyController : Controller
{
    public ActionResult Index()
    {
        MyClass myClass = new MyClass();
        // Your code here
    }
}

namespace MyApp.Models
{
    public class MyClass
    {
        // Your code here
    }
}

namespace MyApp.Controllers
{
    public class MyController : Controller
    {
        public ActionResult Index()
        {
            MyClass myClass = new MyClass();
            // Your code here
        }
    }
}