#include <GDIPlus.au3>
#include <GuiConstantsEx.au3>
#include <WindowsConstants.au3>
#include <WINAPI.au3>
Opt("GUIOnEventMode", 1)

_GDIPlus_Startup()
Global $Image1 = _GDIPlus_ImageLoadFromFile("test.bmp")
   $width=_GDIPlus_ImageGetWidth($Image1)
   $height=_GDIPlus_ImageGetHeight($Image1)
Global Const $AC_SRC_ALPHA = 1
Global $mainWindow    = GUICreate("Setup", 420, 235, @DesktopWidth / 2 - 160, @DesktopHeight / 2 - 145, -1, -1)
$pic=GUICtrlCreatePic("",0,0,$width,$height)
GUISetState()
$Image1=ImageColorToTransparent($Image1, 0xff0000)
Global $Graphic = _GDIPlus_GraphicsCreateFromHWND(GUICtrlGetHandle($pic))
_GDIPlus_GraphicsDrawImageRect($Graphic, $Image1,0,0,$width,$height)
Global $btnInstall    = GUICtrlCreateButton("Click me", 310, 124, 100, 23)

;~ Events
GUICtrlSetOnEvent($btnInstall, "Clickme")

;~ Special Events
GUISetOnEvent($GUI_EVENT_CLOSE, "SpecialEvents")
GUISetOnEvent($GUI_EVENT_MINIMIZE, "SpecialEvents")
GUISetOnEvent($GUI_EVENT_RESTORE, "SpecialEvents")

While 1
    $MSG = GUIGetMsg()
    Switch $MSG
        Case -3
            Quit()
    EndSwitch
WEnd

Func Quit()
    _GDIPlus_ImageDispose($Image1)
    _GDIPlus_GraphicsDispose($Graphic)
    _GDIPlus_Shutdown()
    Exit
EndFunc

Func Clickme()
   MsgBox(0, "Info", "Test")
   Return 0
EndFunc
;$iColor - Colour to be made transparent. Hex colour format 0xRRGGBB. If Default used then top left pixel colour of image
; is used as the transparent colour.
Func ImageColorToTransparent($hImage2, $iColor = Default)
    Local $hBitmap1, $Reslt, $width, $height, $stride, $format, $Scan0, $v_Buffer, $v_Value, $iIW, $iIH

    $GuiSizeX = _GDIPlus_ImageGetWidth($hImage2)
    $GuiSizeY = _GDIPlus_ImageGetHeight($hImage2)
    $hBitmap1 = _GDIPlus_BitmapCloneArea($hImage2, 0, 0, $GuiSizeX, $GuiSizeY, $GDIP_PXF32ARGB)
    If $iColor = Default Then $iColor = GDIPlus_BitmapGetPixel($hBitmap1, 1, 1); Transparent color
    ProgressOn("","Processing", "0 percent", "", @DesktopHeight-80, 1)
    $Reslt = _GDIPlus_BitmapLockBits($hBitmap1, 0, 0, $GuiSizeX, $GuiSizeY, BitOR($GDIP_ILMREAD, $GDIP_ILMWRITE), $GDIP_PXF32ARGB)
;Get the returned values of _GDIPlus_BitmapLockBits ()
    $width = DllStructGetData($Reslt, "width")
    $height = DllStructGetData($Reslt, "height")
    $stride = DllStructGetData($Reslt, "stride")
    $format = DllStructGetData($Reslt, "format")
    $Scan0 = DllStructGetData($Reslt, "Scan0")
    For $i = 0 To $GuiSizeX - 1
        For $j = 0 To $GuiSizeY - 1
            $v_Buffer = DllStructCreate("dword", $Scan0 + ($j * $stride) + ($i * 4))
            $v_Value = DllStructGetData($v_Buffer, 1)
            If Hex($v_Value, 6) = Hex($iColor, 6) Then
                DllStructSetData($v_Buffer, 1, Hex($iColor, 6)); Sets Transparency here. Alpha Channel = 00, not written to.
            EndIf
        Next
        ProgressSet(Int(100 * $i / ($GuiSizeX)), Int(100 * $i / ($GuiSizeX)) & " percent")
    Next
    _GDIPlus_BitmapUnlockBits($hBitmap1, $Reslt)
    ProgressOff()
    Return $hBitmap1
EndFunc  ;==>ImageColorToTransparent

;The GetPixel method gets the color of a specified pixel in this bitmap.
Func GDIPlus_BitmapGetPixel($hBitmap, $iX, $iY)
    Local $tArgb, $pArgb, $aRet
    $tArgb = DllStructCreate("dword Argb")
    $pArgb = DllStructGetPtr($tArgb)
    $aRet = DllCall($ghGDIPDll, "int", "GdipBitmapGetPixel", "hwnd", $hBitmap, "int", $iX, "int", $iY, "ptr", $pArgb)
    Return "0x" & Hex(DllStructGetData($tArgb, "Argb"))
EndFunc  ;==>GDIPlus_BitmapGetPixel

;~ Function for the special events (Close, Minimise and Maximize)
Func SpecialEvents()
   Select
	  Case @GUI_CtrlId = $GUI_EVENT_CLOSE
		 quit()
	  Case @GUI_CtrlId = $GUI_EVENT_MINIMIZE
		 WinSetState ( $mainWindow, "", @SW_MINIMIZE)
	  Case @GUI_CtrlId = $GUI_EVENT_RESTORE
;~ 		 We can use the line below, but it doesn't solve all the poblems like if the MsgBox is opened
;~ 		 _GDIPlus_GraphicsDrawImageRect($Graphic, $Image1, 0, 0, $width, $height)
   EndSelect
EndFunc