Session is null when calling method from one controller to another...MVC

Question

I have an ASP.NET MVC app and i added a new controller to it and call a method from this new controller from an existing controller. I am using session variables and in controller A i call the method in controller B:

if (Session["Grid"] != null){}//session object is fine here
      ControllerB b  = new ControllerB ();
b.CallMethod();

In the new controller, which i'm calling B, the method looks like this:

public object CallMethod(){
    if (Session["Grid"] != null)//session object is null
        {
            //do my thing
        }
  }

The session variable isnt the problem, its the session object. Its completely null, hence my application blows up. The session is alive and well in controller A, so why is it null in controller B? Thank you

Answer 1

That's because ControllerB needs to initializes itself, and as part of this process it also sets Session, Request, Resposne etc accordingly.

So, you need to call the Initialize() method and pass it the current RequestContext. But, since it's marked as protected (because it wasn't meant to be called directly, only using the ControllerFactory), you'll have to expose it:

public class ControllerB : Controller
{
    public void InitializeController(RequestContext context)
    {
        base.Initialize(context);
    }
}

Then in your ControllerA:

var controllerB = new ControllerB();
controllerB.InitializeController(this.Request.RequestContext);

Alternatively, since the Session getter is actually a shorthand for this.ControllerContext.HttpContext.Session (same for Request, Response etc), you can set the ControllerContext instead:

var controllerB = new ControllerB();
controllerB.ControllerContext = new ControllerContext(this.Request.RequestContext, controllerB);

See MSDN