How to change gtk theme in GTK # on Windows?

Question

I need to change the GUI theme in GTK #. I tried something, but it is still far from ideal. Here is my code:

string Resource_File = "Black-Diamond\\gtk-2.0\\gtkrc"; Application.Init (); if (System.IO.File.Exists (Resource_File)) { Gtk.Rc.AddDefaultFile (Resource_File); Gtk.Rc.Parse (Resource_File); } else { ; } MainWindow win = new MainWindow (); win.Show (); Application.Run (); 

Conclusion:

This is normal, but not what I expected (some elements do not look in the original theme ).

Can you tell me how can I change the GUI theme in GTK # on windows? Thanks!