Question

In my SharePoint 2010 c# / asp.net site, I have a class defined like

namespace PDF_Library.VisualWebPart1
{
    public partial class PDF_Library : Usercontrol   
    {
         public static PDF_Library current;
         protected void Page_Load(object sender, EventArgs e)
         {
              current = (PDF_Library)this; 
         }
    }
}


public static class Page_State
{
    public static Page is_display()
    {
        return PDF_Library.current.Page; // didn't work...
    }
}

It doesn’t have a constructor.
How can I get the reference to the current instance of this class?

I tried something like this in the top

public static PDF_Library current;

Then in a function it had

current = (PDF_Library)this;

But that didn’t work…

Answer 1

You need to understand that it does not work this way. Your question is tagged with asp.net – multi-user, multi-threaded environment where multiple instances of PDF_Library user control will be created all the time. It is absolutely uncertain which one of them will be hanging off PDF_Library.current. You need to rethink your design.

More on this: Page instance is disposed of when the request processing is finished. Normally this instance with all its controls and things such as Response, Request, Context etc will be set for garbage collection. Because you keep a reference to a UserControl instance in a static field, all these objects (including Page) will be kept in memory until this current reference is replaced with something else.