GDI+ and IUnknown-IStream interface

[Patrice Terrier]

Merci José.


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Patrice Terrier
mailto[email protected][email protected]</A>
www.zapsolution.com
Addons: WinLIFT (Skin Engine), GDI+ helper (Graphic package), Artwork (logo creation)

[José Roca]

I was going to send you the PB example when I have noticed your post

%GMEM_MOVEABLE       = &H2
%GMEM_NODISCARD      = &H20

TYPE GdiplusStartupInput
   GdiplusVersion AS LONG             ' Must be 1
   DebugEventCallback AS LONG         ' Ignored on free builds
   SuppressBackgroundThread AS LONG   ' FALSE unless you're prepared to call
                                      ' the hook/unhook functions properly
   SuppressExternalCodecs AS LONG     ' FALSE unless you want GDI+ only to use
                                      ' its internal image codecs.
END TYPE

DECLARE SUB MoveMemory LIB "KERNEL32.DLL" ALIAS "RtlMoveMemory" (pDestination AS ANY, pSource AS ANY, BYVAL cbLength AS LONG)
SUB CopyMemory (BYVAL pDestination AS DWORD, BYVAL pSource AS DWORD, BYVAL cbLength AS LONG)
  MoveMemory BYVAL pDestination, BYVAL pSource, cbLength
END SUB

DECLARE FUNCTION GlobalAlloc LIB "KERNEL32.DLL" ALIAS "GlobalAlloc" (BYVAL wFlags AS DWORD, BYVAL dwBytes AS DWORD) AS LONG
DECLARE FUNCTION GlobalFree LIB "KERNEL32.DLL" ALIAS "GlobalFree" (BYVAL hMem AS DWORD) AS LONG
DECLARE FUNCTION GlobalLock LIB "KERNEL32.DLL" ALIAS "GlobalLock" (BYVAL hMem AS DWORD) AS DWORD
DECLARE FUNCTION GlobalUnlock LIB "KERNEL32.DLL" ALIAS "GlobalUnlock" (BYVAL hMem AS DWORD) AS LONG

DECLARE FUNCTION GdipCreateBitmapFromStream LIB "gdiplus.dll" ALIAS "GdipCreateBitmapFromStream" (Byval pstream as Dword, nBitmap As Long) AS LONG

DECLARE FUNCTION GdiplusStartup LIB "gdiplus.dll" ALIAS "GdiplusStartup" (token&, inputbuf AS GdiplusStartupInput, OPTIONAL BYVAL outputbuf&) AS LONG
DECLARE FUNCTION GdiplusShutdown LIB "gdiplus.dll" ALIAS "GdiplusShutdown" (BYVAL token&) AS LONG
DECLARE FUNCTION GdipLoadImageFromStream LIB "gdiplus.dll" ALIAS "GdipLoadImageFromStream" (BYVAL stream AS DWORD, nImage&) AS LONG
DECLARE FUNCTION CreateStreamOnHGlobal LIB "ole32.dll" ALIAS "CreateStreamOnHGlobal" (BYVAL hGlobal AS DWORD, BYVAL fDeleteOnRelease AS DWORD, pstm AS DWORD) AS LONG

FUNCTION GdipStart() EXPORT AS LONG
    DIM GpInput AS GdiplusStartupInput
    GpInput.GdiplusVersion = 1
    IF GdiplusStartup(hGDIplus&, GpInput) = 0 THEN FUNCTION = hGDIplus&
END FUNCTION

SUB GdipEnd(BYVAL hGDIplus&)
    IF hGDIplus& THEN CALL GdiplusShutdown(hGDIplus&): hGDIplus& = 0
END SUB

FUNCTION IUnknown_Release (BYVAL pthis AS DWORD PTR) AS DWORD
    LOCAL DWRESULT AS DWORD
    IF pthis THEN
       CALL DWORD @@pthis[2] USING IUnknown_Release(pthis) TO DWRESULT
       FUNCTION = DWRESULT
    END IF
END FUNCTION

FUNCTION PBMAIN()

    DIM iImageStream AS DWORD, hImage AS LONG, hGDIplus AS LONG

    DIM imageSize AS LONG, sBuffer AS STRING, hGlobal AS DWORD, pGlobalBuffer AS DWORD

    hGDIplus = GdipStart

    sFilename$ = "genus.jpg"
    hFile& = FreeFile
    Open sFilename$ For Binary Access Read Shared As #hFile&
    imageSize = LOF(hFile&)
    sBuffer = SPACE$(imageSize)
    Get #hFile&, , sBuffer
    Close #hFile&


    hGlobal = GlobalAlloc(%GMEM_MOVEABLE OR %GMEM_NODISCARD, imageSize)
    IF hGlobal THEN
       pGlobalBuffer = GlobalLock(hGlobal)
       IF pGlobalBuffer THEN
          CopyMemory pGlobalBuffer, STRPTR(sBuffer), imageSize
          IF CreateStreamOnHGlobal(hGlobal, BYVAL 0&, iImageStream) = 0 THEN
             Ret& = GdipCreateBitmapFromStream(iImageStream, hImage)
             IF Ret& THEN
                MSGBOX "Couldn't Load Image" + str$(Ret&) ' %GpStatusInvalidParameter = 2
             ELSE
                MSGBOX "It's good"
             END IF
             CALL IUnknown_Release(iImageStream)
          END IF
          GlobalUnlock pGlobalBuffer
       END IF
       GlobalFree hGlobal
    END IF

    CALL GdipEnd(hGDIplus)

END FUNCTION

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[This message has been edited by José Roca (edited November 23, 2005).]

[Patrice Terrier]

I am unable to use the GdipLoadImageFromStream,
the function always fails because of invalid parameter in the
IStream interface (I have never been comfortable with COM)

TYPE GdiplusStartupInput
   GdiplusVersion AS LONG             ' Must be 1
   DebugEventCallback AS LONG         ' Ignored on free builds
   SuppressBackgroundThread AS LONG   ' FALSE unless you're prepared to call
                                      ' the hook/unhook functions properly
   SuppressExternalCodecs AS LONG     ' FALSE unless you want GDI+ only to use
                                      ' its internal image codecs.
END TYPE

DECLARE FUNCTION GdiplusStartup LIB "gdiplus.dll" ALIAS "GdiplusStartup" (token&, inputbuf AS GdiplusStartupInput, OPTIONAL BYVAL outputbuf&) AS LONG
DECLARE FUNCTION GdiplusShutdown LIB "gdiplus.dll" ALIAS "GdiplusShutdown" (BYVAL token&) AS LONG
DECLARE FUNCTION GdipLoadImageFromStream LIB "gdiplus.dll" ALIAS "GdipLoadImageFromStream" (BYVAL stream AS DWORD, nImage&) AS LONG
DECLARE FUNCTION CreateStreamOnHGlobal LIB "ole32.dll" ALIAS "CreateStreamOnHGlobal" (BYVAL hGlobal AS DWORD, BYVAL fDeleteOnRelease AS DWORD, pstm AS DWORD) AS LONG

FUNCTION GdipStart() EXPORT AS LONG
    DIM GpInput AS GdiplusStartupInput
    GpInput.GdiplusVersion = 1
    IF GdiplusStartup(hGDIplus&, GpInput) = 0 THEN FUNCTION = hGDIplus&
END FUNCTION

SUB GdipEnd(BYVAL hGDIplus&)
    IF hGDIplus& THEN CALL GdiplusShutdown(hGDIplus&): hGDIplus& = 0
END SUB

FUNCTION IUnknown_Release (BYVAL pthis AS DWORD PTR) AS DWORD
    LOCAL DWRESULT AS DWORD
    IF pthis THEN
       CALL DWORD @@pthis[2] USING IUnknown_Release(pthis) TO DWRESULT
       FUNCTION = DWRESULT
    END IF
END FUNCTION

FUNCTION PBMAIN()
    DIM IStream AS DWORD
    DIM hImage AS LONG, hGDIplus AS LONG

    hGDIplus = GdipStart
          
    sFilename$ = "genus.jpg"
    hFile& = FreeFile
    Open sFilename$ For Binary Access Read Shared As #hFile&
    ReDim m_ImageData(0 To LOF(hFile&) - 1) AS BYTE
    Get #hFile&, , m_ImageData(0)
    Close #hFile&
    If CreateStreamOnHGlobal(m_ImageData(0), BYVAL 0&, IStream) = 0 Then
        Ret& = GdipLoadImageFromStream([b]IStream[/b], hImage)
        IF Ret& Then
            MSGBOX "Couldn't Load Image" + str$(Ret&) ' %GpStatusInvalidParameter = 2 
        else
            MSGBOX "It's good"
        End If
        CALL IUnknown_Release(IStream)
    End If
    CALL GdipEnd(hGDIplus)

END FUNCTION

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Patrice Terrier
mailto[email protected][email protected]</A>
www.zapsolution.com
Addons: WinLIFT (Skin Engine), GDI+ helper (Graphic package), Artwork (logo creation)