Code:
#include <GuiConstants.au3>
#include <GuiConstantsEx.au3>
#include <GDIplus.au3>
#include <misc.au3>
_GDIPlus_Startup()
Global $Dll = DllOpen("user32.dll")
Global $first = True,$finish = False,$Start,$End,$brush = _GDIPlus_BrushCreateSolid(0xA100FF00),$Graphics
$HWND = GuiCreate("Settings",@DesktopWidth,@DesktopHeight,0,0,$WS_POPUP,$WS_EX_TOPMOST)
WinSetTrans("Settings","",100)
$Graphics = _GDIPlus_GraphicsCreateFromHWND($HWND)
GUISetState(@SW_SHOW,$HWND)
While 1
If _IsPressed("1B",$Dll) Then ExitLoop
If _IsPressed("01",$Dll) Then
If $first = True Then
$Start = MouseGetPos()
$first = False
EndIf
$End = MouseGetPos()
_GDIPlus_GraphicsFillRect($Graphics,$Start[0],$Start[1],$End[0] - $Start[0],$End[1] - $Start[1],$brush)
Else
$first = True
EndIf
WEnd
Start array ist oben und links end ist unten und rechts