Cannot use HttpContext.Session in asp.net core

Question

I've added app.UseSession(); to my startup.Configure and services.AddSession() to my ConfigureServices.

Now if I try to use Session like this:

HttpContext.Session.SetString("Type", tableName);

I get "an object reference is required for the non-static field, method or property, 'HttpContext.Session'"

However, if I try to instantiate it like this: HttpContext context = new HttpContext();

it says: "Cannot create an instance of the abstract class or interface 'HttpContext"

How can I access session?

IQuery.cs

using Microsoft.AspNetCore.Http;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;

namespace AppName.Services
{
    public interface IQuery
    {
        List<Dictionary<string, string>> GetListOfDatabases(string dbName);
    }
    public class InMemoryIquery : IQuery
    {
        public List<Dictionary<string, string>> GetListOfDatabases(string tableName)
        {
        if(tableName != null)
            {
               HttpContext.Session.SetString("Type", tableName);
            }
        }
    }

In what context are you accessing it? See [Access HttpContext in ASP.NET Core](https://learn.microsoft.com/en-us/aspnet/core/fundamentals/http-context?view=aspnetcore-3.1) — stuartd, Feb 21 '20 at 11:08
I am trying to access it from within a class that inherits an interface — NickyLarson, Feb 21 '20 at 11:11
Can you post the full code where you are trying to access the Session? — Andre.Santarosa, Feb 21 '20 at 11:12
We can help, if you send the full code of that class that accesses the session. — Milad Dastan Zand, Feb 21 '20 at 11:15
As the docs say _"t's only necessary to use IHttpContextAccessor **when you need access to the HttpContext inside a service**."_ And it looks from your code that that is the case. — stuartd, Feb 21 '20 at 11:27
.. so see [this section](https://learn.microsoft.com/en-us/aspnet/core/fundamentals/http-context?view=aspnetcore-3.1#use-httpcontext-from-custom-components) about how to register and use the accessor — stuartd, Feb 21 '20 at 11:28
see this https://stackoverflow.com/questions/31243068/access-the-current-httpcontext-in-asp-net-core — Milad Dastan Zand, Feb 21 '20 at 11:32

score 4 · Accepted Answer · answered Feb 21 '20 at 11:37

In your class add the IHttpContextAccessor to your constructor and use like this

public class InMemoryIquery : IQuery
{
    private IHttpContextAccessor _httpContextAccessor;

    public InMemoryIquerty(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    public List<Dictionary<string, string>> GetListOfDatabases(string tableName)
    {
    if(tableName != null)
        {
           _httpContextAccessor.HttpContext.Session.SetString("CalculationType", tableName);
        }
    }
}

In your ConfigureServices add the following line services.AddHttpContextAccessor(); after services.AddControllersWithViews();

score 0 · Answer 2 · answered Feb 21 '20 at 11:27

0

In the outside of this class, Use this to get current HttpContext.

HttpContext context = HttpContext.Current;

Then inject it into the constructor of this class. you must have something like this:

public InMemoryIquery(HttpContext httpContext)
{
   httpContext.Session.SetString("CalculationType", tableName);
}

answered Feb 21 '20 at 11:27

Milad Dastan Zand

1,062
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This is not correct in .Net Core, or possibly anywhere. You should use the `HttpContextAccessor` – stuartd Feb 21 '20 at 11:29
oh you right in.net core, see this https://stackoverflow.com/questions/31243068/access-the-current-httpcontext-in-asp-net-core – Milad Dastan Zand Feb 21 '20 at 11:32

Cannot use HttpContext.Session in asp.net core

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