可以用你的程序在屏幕上的任何地方画图，效果就象电子宠物一样很简单，只要两个API 



The first one is getdesktopwindow and the other is getwindowdc 



the detail you can see the Win32 help which was plused in Delphi4 



For example: you paste a bitmap on the screen 



var wnd:longint; 



mydc,bitmapdc:Hdc; 



mybitmap:Tbitmap; 



mybitmap:=Tbitmap.create(); 



mybitmap.loadfromfile('c:\windows\waves.bmp'); 



bitmapdc:=getwindowdc(mybitmap.handle); 



wnd:=getdesktopwindow(); 



mydc:=getwindowdc(wnd); 



bitblt(my....... //I forget the detail if you have any questions can


转自：  编程联盟