[Mono-list] Gtk# problem

[Willem J.W. Semmelink]

Hi everyone

I cannot get the Gdk.Pixmap constructor to work. My app gets a run-time =
exception that the
GdkWindow parameter is null at the line
pixmap =3D new =
Gdk.Pixmap(w.GdkWindow,w.Allocation.width,w.Allocation.height,-1);

My intention with the code below was to draw on a pixmap, and then to =
display the pixmap in=20
a scrolled window. Eventually, I want to keep a list of pixmaps and =
display the one I need=20
in the scrolled window based on certain events.=20

The Gtk# chapter 22 in the Gtk Manual deals with it, but unfortunately, =
the chapter is not=20
written yet in the mono handbook, so I consulted the original manual for =
C, but maybe I=20
misunderstood something- therefore I list my code below.=20

I use Gtk# 0.8 for Windows[gtk-sharp-0.8-win32-2.exe], and Windows XP.=20
I used the Ms csc compiler when I got the error.

Any help appreciated.

using Gtk;
using GtkSharp;
using System;

namespace Test
{
	class Demo
	{
		static Gdk.Pixmap pixmap=3Dnull;
		public static int Main(string[] args)
		{
			Application.Init();
			Gtk.Window win =3D new Gtk.Window ("ScrollBox With Picture");
			win.DeleteEvent +=3D new DeleteEventHandler(Window_Delete);
		=09
			Gtk.ScrolledWindow scrolled_window =3D new Gtk.ScrolledWindow (new =
Adjustment (IntPtr.Zero), new Adjustment (IntPtr.Zero));
		=09
			Gtk.DrawingArea dc =3D new Gtk.DrawingArea();
			dc.SetSizeRequest(80,160);
			scrolled_window.AddWithViewport(dc);	=09
			dc.Show();					=09

			scrolled_window.SetPolicy (PolicyType.Automatic, =
PolicyType.Automatic);
			win.Add (scrolled_window);
			win.ShowAll ();

			//This is where my code fails =
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
			pixmap =3D new =
Gdk.Pixmap(w.GdkWindow,w.Allocation.width,w.Allocation.height,-1);
			=
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~=
~~~~

			pixmap.DrawRectangle(w.Style.WhiteGC,1,10,10,100,100);
	=09
			Application.Run ();
			return 0;
		}=09

		static void Window_Delete(object obj, GtkSharp.DeleteEventArgs args)
		{
			SignalArgs sa =3D (SignalArgs) args;
			Application.Quit();
			sa.RetVal =3D true;
		}	=09
	}
}