Code snippet that shows how to paint in another application's window or on the screen itself.
Ever wished to paint in the window of Word, or on the desktop? Have a look at this:
procedure TForm1.Button1Click(Sender: TObject);
var thehandle:thandle;
thecanvas:tcanvas;
begin
thecanvas:=tcanvas.create;
winexec('notepad.exe',sw_normal);
thehandle:=findwindow('notepad',nil);
thecanvas.handle:=getdc(thehandle);
thecanvas.rectangle(0,0,100,100);
thecanvas.free;
end;
For painting the screen itself, use:
thecanvas.handle:=createdc('DISPLAY',Nil,Nil,Nil);