Following upon this, I found myself wondering if static state will persist across the changing of "pages" in a stateless web application. It turns out that it will! If you have something like so managing a counter...
namespace MvcApplication.Models
{
public static class Counter
{
public static int Count;
}
}
...the counter will grow (without getting confused or resetting) as you switch back and forth between two actions in a controller (in an ASP.NET MVC4 Web API application with C# in this case) as seen here:
using System.Web.Mvc;
using MvcApplication.Models;
namespace MvcApplication.Controllers
{
public class HomeController : Controller
{
public ActionResult Index()
{
return View(++Counter.Count);
}
public ActionResult About()
{
return View(++Counter.Count);
}
}
}
We can drive the upfront assignment of our counter from Global.asax.cs like so:
using System.Web.Http;
using System.Web.Mvc;
using System.Web.Optimization;
using System.Web.Routing;
using MvcApplication.Models;
namespace MvcApplication
{
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
Counter.Count = 0;
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
}
}
}
When I did this in Cassini I noticed that I could open two different browsers and the two browsers together would affect each other's counters and bias each others numbers. (They both dogpiled onto the counter.) Also, I noticed that if I closed all browsers, stopped the application, and restarted it, the the counter did not reset to zero. Only restarting Visual Studio allowed for a reset back to zero. This seemed imperfect so I tried this instead:
using System.Web.Http;
using System.Web.Mvc;
using System.Web.Optimization;
using System.Web.Routing;
using MvcApplication.Models;
namespace MvcApplication
{
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
}
protected void Session_Start()
{
Counter.Count = 0;
}
}
}
Well, this got rid of the need to restart the application. I was able to just close all browsers to set the counter back to zero. However, different browsers still shared state! I then remembered I was using Cassini which only has one session. I switched to using IIS and the counter then only incremented based on browser session as desired!
