BWPM/App/Controllers/HomeController.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using APP.Models;
using Microsoft.AspNetCore.Http;

namespace APP.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }

        public IActionResult Index()
        {
            HttpContext.Session.SetString("SessionVariable1", "Testing123");
            return View();
        }

        public IActionResult Privacy()
        {
            ViewBag.Message = HttpContext.Session.GetString("SessionVariable1");
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }

        public IActionResult Login()
        {
            HttpContext.Session.SetString("ShowLogin", "True");
            ViewBag.showlogin = "True";
            return View();
        }
    }
}