PNG/JPG file to HBITMAP with GDI+

Asked Jul 27 '15 at 09:36

Active Aug 18 '15 at 07:44

Viewed 4,744 times

I need to load an image as a HBITMAP in C++ so I can send it to a printer. I've tried using Gdiplus::Bitmap::FromFileand then Gdiplus::Bitmap->GetHBITMAP however the HBITMAP returned is still empty.

I can load .bmp files fine with LoadImage() but this doesn't work with PNG files.

Could anyone point me to the correct way of implementing this to work with .png (and more, if possible) file types?

EDIT: CODE

ZeroMemory(&hBitmap, sizeof(HBITMAP));
Gdiplus::Bitmap* gpBitmap = Gdiplus::Bitmap::FromFile(L"img.png");
gpBitmap->GetHBITMAP(0, &hBitmap);

EDIT 2: Solution found

HBITMAP GetHBITMAPFromImageFile(WCHAR* pFilePath)
{
    GdiplusStartupInput gpStartupInput;
    ULONG_PTR gpToken;
    GdiplusStartup(&gpToken, &gpStartupInput, NULL);
    HBITMAP result = NULL;
    Gdiplus::Bitmap* bitmap = Gdiplus::Bitmap::FromFile(pFilePath, false);
    if (bitmap)
    {
        bitmap->GetHBITMAP(Color(255, 255, 255), &result);
        delete bitmap;
    }
    GdiplusShutdown(gpToken);
    return result;
}

edited Aug 18 '15 at 07:44

asked Jul 27 '15 at 09:36

ChappieZ

`Gdiplus::Bitmap::GetHBITMAP` is supposed to work. If it doesn't, then you're possibly doing something wrong. However, we can't tell if you don't provide code demonstrating how you're using it. – jamesdlin Jul 27 '15 at 09:41
Are you sure that 1. the program is defined as unicode 2. the png is in the executable directory? – David Haim Jul 27 '15 at 09:48
I just have the png in that directory for demonstration purposes – ChappieZ Jul 27 '15 at 09:58
@DavidHaim Instead of in the executable directory, the file should be in the working directory. – Mark Jansen Jul 27 '15 at 10:01
Are you calling `GdiplusStartup()` ? – Jonathan Potter Jul 27 '15 at 12:40
I am, but Is `GdiplusStartup()` an essential call to have? – ChappieZ Jul 27 '15 at 13:21
Have you checked whether `Gdiplus::Bitmap::FromFile` and `GetHBITMAP` actually succeed? How do you know that the returned `HBITMAP` is empty? – jamesdlin Jul 27 '15 at 18:04

PNG/JPG file to HBITMAP with GDI+

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