Why $WS_EX_LAYERED does not work?

[azhuang]

Hi all,

 

I created a GUI window with $WS_EX_LAYERED style, then used _WinAPI_BltBit API with parameter $SRCCOPY (no $CAPTUREBLT) to copy the desktop to the GUI window. What I want is captured the background which was covered by the GUI window.

 

However, the Bitblt can still captured the GUI window, not the background. How can I do to get the background instead?

 

#include <GuiConstantsEx.au3>
#include <WindowsConstants.au3>
#include <Misc.au3>
#include <WinAPIGdi.au3>

Opt("GUIOnEventMode", 1)
Opt("MouseCoordMode", 1)

$ZoomSizeX = 256
$ZoomSizeY = 256

$ZoomGUI = GUICreate("Capture Backgroud", $ZoomSizeX, $ZoomSizeY, 400, 200, BitOR($WS_SIZEBOX,$WS_THICKFRAME, $WS_SYSMENU, $WS_BORDER, $WS_CAPTION), BitOR($WS_EX_LAYERED,  $WS_EX_TOPMOST, $WS_EX_TRANSPARENT) )
_WinAPI_SetLayeredWindowAttributes($ZoomGUI,  0, 255, $LWA_ALPHA)

GUISetState()

Main()

Func Main()
    Local $aMPosNew
    Local $dll = DllOpen("user32.dll")

    Do
        $ZoomDC = _WinAPI_GetDC($ZoomGUI)
        $DeskDC = _WinAPI_GetDC(0)

        $aMPosNew = MouseGetPos()
        _WinAPI_BitBlt($ZoomDC, 0, 0, $ZoomSizeX, $ZoomSizeY, $DeskDC, $aMPosNew[0], $aMPosNew[1],  $SRCCOPY )

        _WinAPI_ReleaseDC(0, $DeskDC)
        _WinAPI_ReleaseDC($ZoomGUI, $ZoomDC)
        Sleep(10)
    Until _IsPressed("1B", $dll); ESC key
EndFunc   ;==>Main

Thanks

 

[UEZ]

Have a look to >Pseudo Aero Look where I copy the desktop background under the GUI to the GUI.

 

 

Br,

UEZ

Edited September 7, 2013 by UEZ

[azhuang]

Thanks UEZ, I don't know why need we to disable DWM? There is a windows tool "magnifier" can capture the background no need to disable it.

[PhoenixXL]

WM_PRINTCLIENT | WM_PRINT  - Might be useful, but its not perfect..!!