why CreateDIBSection() fails with certian BITMAPINFO?

Question

I am trying to use CreateDIBSection.

Problem:

In Windows XP, I tried to call CreateDIBSection, it returns NULL and GetLastError = 0

When I try to change the screen resolution, for example to 2048 x 1536, it returns correct value.

I have tested this function has some relationship with nMemSize (not necessarily small number).

Question:

Is there any guarantee way to ensure CreateDIBSection returns correct value?

nScreenWidth = 1024;
nScreenHeight= 768;
 = nScreenWidth*nScreenHeight*3*7
HDC hdc = ::GetDC(hWnd);
m_hBmpMapFile = ::CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, nMemSize, NULL);

BITMAPINFO bmpInfo = {0};
bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmpInfo.bmiHeader.biWidth = nScreenWidth;
bmpInfo.bmiHeader.biHeight = nScreenHeight;
bmpInfo.bmiHeader.biPlanes = 1;
bmpInfo.bmiHeader.biBitCount = 24;
bmpInfo.bmiHeader.biCompression = 0;
bmpInfo.bmiHeader.biSizeImage = nMemSize;
bmpInfo.bmiHeader.biXPelsPerMeter = 0;
bmpInfo.bmiHeader.biYPelsPerMeter = 0;
bmpInfo.bmiHeader.biClrUsed = 0;
bmpInfo.bmiHeader.biClrImportant = 0;
bmpInfo.bmiColors[0].rgbBlue = 204;
bmpInfo.bmiColors[0].rgbGreen = 204;
bmpInfo.bmiColors[0].rgbRed = 204;
bmpInfo.bmiColors[0].rgbReserved = 0;
PVOID pvBits;

m_hBmpAllWstDskWallpaper = ::CreateDIBSection(hdc, &bmpInfo, DIB_RGB_COLORS, &pvBits, m_hBmpMapFile, 0);

Well, it's not clear why it's failing. I think your question should really be, "why is CreateDIBSection failing?". If you can get an answer to that then you should be able to solve your real problem. — David Heffernan, Jan 18 '11 at 09:59
ok, I have changed it. I think the reail problem is really CreateDIBSection fails when nMemSize change to certian number. sometimes it fails with say 10000, but when u change nMemsize to a larger 20000 it succesed. — yyy, Jan 18 '11 at 10:15
@yyy: Post all fields of `bmpinfo.bmiHeader`. What values you assign to them? — Nawaz, Jan 18 '11 at 10:21
Please provide the complete code. It would be much easier for us to tell (or guess) where the problem might be. And why is it `* 7` in the `nMemSize` equation? — detunized, Jan 18 '11 at 10:23
sorry i just edited. `*3` for RGB bytes, `*7` is for 7 times the screen size. i am making a large horizontal panorama screen. — yyy, Jan 18 '11 at 10:46
Works fine with my windows 7 machine. Could it actually be another API function failing? Have you tried calling GetLastError after other API calls? — MW_dev, Jan 18 '11 at 11:32

MW_dev · Answer 1 · 2011-01-18T11:31:11.327

I suspect the problem might be contained in the section of code that you did not include (in the elipses ...). So I recommend:

Check your Device Context is valid
ZeroMemory
Add the structure size
And bitmap dimensions
Move the GetLastError calls to ensure that the Device Context is valid (perhaps an earlier API call fails)

The code below seems to work after I added the recommendations above, I hope it helps:

        HDC hdc = ::GetDC(hWnd); 
        int nScreenWidth = 1024; 
        int nScreenHeight= 768; 
        int nMemSize = nScreenWidth*nScreenHeight*3*7;
        HANDLE m_hBmpMapFile = ::CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, nMemSize, NULL); 
        BITMAPINFO bmpInfo; 
        //clear the memory
        ZeroMemory(&bmpInfo.bmiHeader, sizeof(BITMAPINFOHEADER));
        //struct size
        bmpInfo.bmiHeader.biSize = sizeof (BITMAPINFOHEADER);
        //dimensions
        bmpInfo.bmiHeader.biWidth = nScreenWidth;
        bmpInfo.bmiHeader.biHeight = nScreenHeight;
        bmpInfo.bmiHeader.biPlanes = 1; 
        bmpInfo.bmiHeader.biBitCount = 32; 
        bmpInfo.bmiHeader.biSizeImage=nMemSize; 
        void *pvBits = NULL;
        HANDLE m_hBmpAllWstDskWallpaper = ::CreateDIBSection(hdc, &bmpInfo, DIB_RGB_COLORS, &pvBits, m_hBmpMapFile, 0);
        int nError = ::GetLastError();

why CreateDIBSection() fails with certian BITMAPINFO?

1 Answers1