GDI+ & GDI: need to call _GDIPlus_ImageSaveToFile after GDI drawing

[Zedna]

I have GUI with picture control where I do some GDI drawing.

Now I need to save its content as BMP or PNG image to disk.

I think the best will be using _GDIPlus_ImageSaveToFile() for this but there is problem how to obtain hImage from my hDC.

I need the idea, maybe I'm doing this completely wrong or there is another easy way for saving GDI drawing from hDC to file.

Here is code with some my attempts commented:

Result is black image in PNG.

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#include <GUIConstants.au3>
#include <WinAPI.au3>
#include <GDIPlus.au3>

Global $gdi_dll = DllOpen("gdi32.dll")

$gui = GUICreate("GDI+",400,300)
$pic = GUICtrlCreatePic("",0,0,400,300)
;~ $pic = GUICtrlCreateLabel("",0,0,400,300)
$pic_hWnd = ControlGetHandle($gui,"",$pic)
$pic_hdc = _WinAPI_GetDC($pic_hWnd)
GUIRegisterMsg($WM_PAINT, "MY_WM_PAINT")
GUISetState(@SW_SHOW)

_GDIPlus_Startup ()

$hGraphic = _GDIPlus_GraphicsCreateFromHDC ($pic_hdc)
;~ $hGraphic = _GDIPlus_GraphicsCreateFromHWND ($pic_hWnd)

; some GDI+ painting - just test
_GDIPlus_GraphicsDrawString ($hGraphic, "Hello world", 150, 150)
$hPen = _GDIPlus_PenCreate (0xFFFF0000,2,2)
_GDIPlus_GraphicsDrawRect ($hGraphic, 200, 200, 50, 50, $hPen)

;~ $hGraphic = _GDIPlus_ImageGetGraphicsContext ($hImage) ; I need opposite of this

;~ $hImage = _GDIPlus_BitmapCreateFromHBITMAP($hBmp[, $hPal = 0])
$hImage = _GDIPlus_BitmapCreateFromGraphics(400, 300, $hGraphic) ; not sure here ...
_GDIPlus_ImageSaveToFile ($hImage, @ScriptDir & "\GDIPlus_Image.png")

_GDIPlus_PenDispose ($hPen)
_GDIPlus_GraphicsDispose ($hGraphic)
_GDIPlus_ImageDispose ($hImage)
_GDIPlus_ShutDown ()

While 1
 $msg = GUIGetMsg()
 If $msg = $GUI_EVENT_CLOSE Then ExitLoop
WEnd

_WinAPI_ReleaseDC($pic_hWnd, $pic_hdc)

Func DrawRedCross($bez_snimku = 0) ; GDI drawing
 $x = 100
 $y = 100
 $pen = DLLCall($gdi_dll,"int","CreatePen","int",0,"int",1,"int",0xFF)
 $obj_orig = DLLCall($gdi_dll,"int","SelectObject","int",$pic_hdc,"int",$pen[0])
 DLLCall($gdi_dll,"int","MoveToEx","int",$pic_hdc,"int",$x,"int",$y-10,"int",0)
 DLLCall($gdi_dll,"int","LineTo","int",$pic_hdc,"int",$x,"int",$y+11) ;vertical line
 DLLCall($gdi_dll,"int","MoveToEx","int",$pic_hdc,"int",$x-10,"int",$y,"int",0)
 DLLCall($gdi_dll,"int","LineTo","int",$pic_hdc,"int",$x+11,"int",$y) ;horizontal line
 DLLCall($gdi_dll,"int","SelectObject","int",$pic_hdc,"int",$obj_orig[0])
 DLLCall($gdi_dll,"int","DeleteObject","int",$pen[0])
EndFunc

Func MY_WM_PAINT($hWnd, $Msg, $wParam, $lParam)
 _WinAPI_RedrawWindow($pic_hWnd, 0, 0, $RDW_UPDATENOW) ; force redraw of pic (Rect=0 Region=0)
 DrawRedCross() ; then draw my stuff on top
 _WinAPI_RedrawWindow($pic_hWnd, 0, 0, $RDW_VALIDATE) ; then force no-redraw of pic
 Return $GUI_RUNDEFMSG
EndFunc

Edited December 30, 2010 by Zedna

[UEZ]

Here one possibility:

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#include <GUIConstants.au3>
#include <WinAPI.au3>
#include <GDIPlus.au3>
#include <WindowsConstants.au3>

Global $gdi_dll = DllOpen("gdi32.dll")

$gui = GUICreate("GDI+",400,300)
$pic = GUICtrlCreatePic("",0,0,400,300)
;~ $pic = GUICtrlCreateLabel("",0,0,400,300)
$pic_hWnd = ControlGetHandle($gui,"",$pic)
$pic_hdc = _WinAPI_GetDC($pic_hWnd)
GUIRegisterMsg($WM_PAINT, "MY_WM_PAINT")
GUISetState(@SW_SHOW)

_GDIPlus_Startup ()

$hGraphic = _GDIPlus_GraphicsCreateFromHDC ($pic_hdc)
;~ $hGraphic = _GDIPlus_GraphicsCreateFromHWND ($pic_hWnd)

; some GDI+ painting - just test
_GDIPlus_GraphicsDrawString ($hGraphic, "Hello world", 150, 150)
$hPen = _GDIPlus_PenCreate (0xFFFF0000,2,2)
_GDIPlus_GraphicsDrawRect ($hGraphic, 200, 200, 50, 50, $hPen)

;~ $hGraphic = _GDIPlus_ImageGetGraphicsContext ($hImage) ; I need opposite of this

;~ $hImage = _GDIPlus_BitmapCreateFromHBITMAP($hBmp[, $hPal = 0])
;~ $hImage = _GDIPlus_BitmapCreateFromGraphics(400, 300, $hGraphic) ; not sure here ...
;~ _GDIPlus_ImageSaveToFile ($hImage, @ScriptDir & "\GDIPlus_Image.png")

_GDIPlus_Save_to_Image(@ScriptDir & "\GDIPlus_Image.png", $gui)

_GDIPlus_PenDispose ($hPen)
_GDIPlus_GraphicsDispose ($hGraphic)
;~ _GDIPlus_ImageDispose ($hImage)
_GDIPlus_ShutDown ()

While 1
 $msg = GUIGetMsg()
 If $msg = $GUI_EVENT_CLOSE Then ExitLoop
WEnd

_WinAPI_ReleaseDC($pic_hWnd, $pic_hdc)

Func DrawRedCross($bez_snimku = 0) ; GDI drawing
 $x = 100
 $y = 100
 $pen = DLLCall($gdi_dll,"int","CreatePen","int",0,"int",1,"int",0xFF)
 $obj_orig = DLLCall($gdi_dll,"int","SelectObject","int",$pic_hdc,"int",$pen[0])
 DLLCall($gdi_dll,"int","MoveToEx","int",$pic_hdc,"int",$x,"int",$y-10,"int",0)
 DLLCall($gdi_dll,"int","LineTo","int",$pic_hdc,"int",$x,"int",$y+11) ;vertical line
 DLLCall($gdi_dll,"int","MoveToEx","int",$pic_hdc,"int",$x-10,"int",$y,"int",0)
 DLLCall($gdi_dll,"int","LineTo","int",$pic_hdc,"int",$x+11,"int",$y) ;horizontal line
 DLLCall($gdi_dll,"int","SelectObject","int",$pic_hdc,"int",$obj_orig[0])
 DLLCall($gdi_dll,"int","DeleteObject","int",$pen[0])
EndFunc

Func MY_WM_PAINT($hWnd, $Msg, $wParam, $lParam)
 _WinAPI_RedrawWindow($pic_hWnd, 0, 0, $RDW_UPDATENOW) ; force redraw of pic (Rect=0 Region=0)
 DrawRedCross() ; then draw my stuff on top
 _WinAPI_RedrawWindow($pic_hWnd, 0, 0, $RDW_VALIDATE) ; then force no-redraw of pic
 Return $GUI_RUNDEFMSG
EndFunc

; #FUNCTION# =============================================================================
; Name.............:        _GDIPlus_Save_to_Image
; Description ...:      INTERNAL FUNCTION - save drawnelements in GUI to file
; Syntax...........:        _GDIPlus_Save_to_Image($file, $hWnd)
; Parameters ...:       $file - filename
;                               $hWnd - handle to GUI
; Author .........:         ptrex, ProgAndy, UEZ
; =========================================================================================
Func _GDIPlus_Save_to_Image($file, $hWnd)
    Local $hDC, $memBmp, $memDC, $hImage, $w, $h, $size, $err, $sCLSID, $ext, $fExt
    If $file <> "" Or $hWnd <> "" Then
        $size = WinGetClientSize($hWnd)
        $w = $size[0]
        $h = $size[1]
        $hDC = _WinAPI_GetDC($hWnd)
        $memDC = _WinAPI_CreateCompatibleDC($hDC)
        $memBmp = _WinAPI_CreateCompatibleBitmap($hDC, $w, $h)
        _WinAPI_SelectObject ($memDC, $memBmp)
        _WinAPI_BitBlt($memDC, 0, 0, $w, $h, $hDC, 0, 0, 0x00CC0020) ;  0x00CC0020 = $SRCCOPY
        $hImage = _GDIPlus_BitmapCreateFromHBITMAP ($memBmp)
        $ext = "png,bmp,jpg,tif,gif"
        $fExt = StringRight($file, 3)
        If Not StringInStr($ext, $fExt)  Then
            $CLSID = "PNG"
            $file &= ".png"
        Else
            $CLSID = $fExt
        EndIf
        $sCLSID = _GDIPlus_EncodersGetCLSID ($CLSID)
        If Not _GDIPlus_ImageSaveToFileEx ($hImage, $file, $sCLSID) Then $err = 1
        _GDIPlus_ImageDispose ($hImage)
        _WinAPI_ReleaseDC($hWnd, $hDC)
        _WinAPI_DeleteDC($memDC)
        _WinAPI_DeleteObject ($memBmp)
        If $err Then Return SetError(2, 0, 0)
        Return SetError(0, 0, 0)
    Else
        Return SetError(1, 0, 0)
    EndIf
EndFunc

Br,

UEZ

Edited December 30, 2010 by UEZ

[Zedna]

Thank you very much UEZ!!

Work like a charm and I'm happy I can do saving of GDI drawing to file now.

I very appreciate your help.

It's working solution but I think principially it's not optimal because it creates new bitmap and does copy of original bitmap.

I'm just curious if there is another more effective way - probably somehow get hBitmap from original DC/hWnd.

EDIT2: In code is

$hImage = _GDIPlus_BitmapCreateFromHBITMAP ($memBmp)

EDIT:

In my real project this bitmap (drawing control) is very large

so that's why I'm scared about efficiency

Edited December 30, 2010 by Zedna