Porting to Cocoa# from WinForms

[Leauki]

Hi,

What is the preferred way of porting a .NET application from WinForms
to Cocoa#?

Should I re-do the entire GUI part and keep only the application
logic? Is there a compatibility layer that maps WinForm controls onto
Cocoa controls? Or is Cocoa# WinForms-compatible (and to what extent)?

Also, is there some points to pay special attention to when developing
an application so that porting it to other GUI frameworks is not too
difficult from the outset? Ideally, my programs should use WinForms on
Windows, GTK# on X11, and Cocoa# on Mac OS X, I presume?