‘Session’ does not exist in the current context

I have the following code, that uses session but i have an error in the line :

if (Session["ShoppingCart"] == null)

the error is cS0103: The name 'Session' does not exist in the current context what is the problem ?

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

using System.Collections.Generic;
using System.Web.SessionState;
/// <summary>
/// Summary description for ShoppingCart
/// </summary>
public class ShoppingCart
{
    List<CartItem> list;
    public ShoppingCart()
    {
        if (Session["ShoppingCart"] == null)
            list = new List<CartItem>();
        else
            list = (List<CartItem>)Session["ShoppingCart"];
    }
}

Answers:

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Method 1

Use

if (HttpContext.Current == null || 
    HttpContext.Current.Session == null || 
    HttpContext.Current.Session["ShoppingCart"] == null)

instead of

if (Session["ShoppingCart"] == null)

Method 2

The issue is that your class does not inherit from Page. you need to Change

public class ShoppingCart

to

public class ShoppingCart : Page

and it will work

Method 3

You either need to convert your class to a Page by inheriting from Page, or have the Session passed in, or use HttpContext.Current.Session.

Method 4

If you want to use session directly then just simply add following namespace

using system.web.mvc

Method 5

In my case only try-catch block fix problem, like this:

protected void Application_AcquireRequestState(object sender, EventArgs e)
    {
        /// Using from Try-Catch to handle "Session state is not available in this context." error.
        try
        {
            //must incorporate error handling because this applies to a much wider range of pages 
            //let the system do the fallback to invariant 
            if (Session["_culture"] != null)
            {
                System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo(Session["_culture"].ToString());
                //it's safer to make sure you are feeding it a specific culture and avoid exceptions 
                System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(Session["_culture"].ToString());
            }
        }
        catch (Exception ex)
        {}
    }

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0