Migration to .NET 5

Question

I am trying to migrate a 4.6.1 .NET framework to .NET 5 but below code is giving error -
Error CS0117 'HttpContext' does not contain a definition for 'Current'

using Disa.Core.Containers;
using System.Web;

namespace Disa.Core.Logging
{
public static class ServiceLocator
{
public static void Set(IContainer container)
{
HttpContext.Current.Items.Add("Container", container);
}

    public static IContainer Get()
    {
        return (IContainer)HttpContext.Current.Items["__Container__"];
    }
}

}

Answer 1

The ASP.NET 5 context works much differently than ASP.NET 4.6.1. HttpContext is accessed through the IHttpContextAccessor interface using dependency injection. Keep in mind, this information is openly published in the .NET 5 fundamental documentation. Below is an example that uses standard constructor injection loosely based on your code example..

    public interface IContainer  
    {  
        string Name { get; set; }  
    }  
  
    public class Container : IContainer  
    {  
        public string Name { get; set; }  
    }  
  
    public interface IServiceLocator  
    {  
        IContainer Get();  
        void Set(IContainer container);  
    }  
  
  
    public class ServiceLocator : IServiceLocator  
    {  
        private readonly IHttpContextAccessor _httpContextAccessor;  
        public ServiceLocator(IHttpContextAccessor httpContextAccessor)  
        {  
            _httpContextAccessor = httpContextAccessor;  
        }  
        public void Set(IContainer container)  
        {  
            _httpContextAccessor.HttpContext.Items.Add("__Container__", container);  
        }  
  
        public IContainer Get()  
        {  
            return (IContainer)_httpContextAccessor.HttpContext.Items["__Container__"];  
        }  
    }  

Register the service in the startup.cs file

services.AddScoped<IServiceLocator, ServiceLocator>();  

Constructor injection and implementation

    public class DiDemoController : Controller  
    {  
        public readonly IServiceLocator _service;  
        public DiDemoController(IServiceLocator service)  
        {  
            _service = service;  
        }  
        public IActionResult Index()  
        {  
            Container container = new Container() { Name = "Hello World" };  
            _service.Set(container);  
  
            ViewBag.Name = _service.Get().Name;  
            return View();  
        }  
    }  

  
@{  
    ViewData["Title"] = "Index";  
}  
  
<h1>Index</h1>  
  
<div>@(ViewBag.Name ?? "Empty") </div>  

Answer 2

For performance reasons the static .HttpContext.Current methods nor any of the other ,Current methods ported to asp.net core.

This means you must pass an HttpContext to the static methods as a parameter. I found this one of the main porting challenge. In addition the use of static methods to access config settings.

For porting I created a static library for settings, and reworked code that called HttpContext.Current., but using an object property rather than a static.