Here's a simple Win32 example:
| hwnd dc dst |
hwnd _ Win32Window getFocus. "fetch the window currently having the focus"
dc _ hwnd getDC. "grab the dc or the window"
dst _ 100.
dc moveTo: 0@0.
"draw a rect"
dc lineTo: dst@0. dc lineTo: dst@dst. dc lineTo: 0@dst. dc lineTo: 0@0.
"and a cross"
dc lineTo: dst@dst. dc moveTo: dst@0. dc lineTo: 0@dst.
hwnd releaseDC: dc.

	api calls
	apiGetDC: apiMessageBox:text:title:flags: apiReleaseDC:with: apiScreenToClient:with:

	examples
	coloredEllipses coloredRectangles win32Draw

	accessing	top
	getDC Return the DC associated with the window
	getHDCDuring: Provide a Win32 HDC during the execution of aBlock
	messageBox: Win32Window getFocus messageBox:'Hello World'
	messageBox:title: Win32Window getFocus messageBox:'Hello World' title:'News from Squeak:'
	messageBox:title:flags: Win32Window getFocus messageBox:'Are you ready???' title:'News from Squeak:' flags: 3
	releaseDC: Release the given DC
	screenToClient:

	api calls	top
	apiGetDC:
	apiMessageBox:text:title:flags:
	apiReleaseDC:with:
	apiScreenToClient:with:

	accessing	top
	getDesktopWindow Return the HWND describing the desktop
	getFocus Return the HWND currently having the input focus

	examples	top
	coloredEllipses Win32Window coloredEllipses
	coloredRectangles Win32Window coloredRectangles
	win32Draw Win32Window win32Draw