Saving bitmaps

[jwkNwA7f]

Hi, I am following a tutorial on saving bitmaps. It has gone well, but I am having a problem now. The program does compile successfully. It can save the file, but when I open the file it says:

Windows Live Photo Gallery wrote:

Photo Gallery can't open this photo or video. The file may be unsupported, damaged or corrupt.

Here are some pieces of the code:
Call to the functions in WndProc():

case SAVE_BM:
			{
				BOOL result = SaveFileDlg(hwnd, filePath, "Save Bitmap");
				if (result)
				{
					PBITMAPINFO pbi = CreateBmpInfoStruct(hwnd, hBitmap);
					hdc = GetDC(hwnd);
					SaveBmpFile(hwnd, filePath, pbi, hBitmap, hdc);
				}
				return 0;
			}

SaveBmpFile():

void SaveBmpFile(HWND hwnd, LPSTR file, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC)
{
	std::ofstream hF;
	BITMAPFILEHEADER bmfh;
	PBITMAPINFOHEADER pbmih;
	LPBYTE bits;
	DWORD total;
	DWORD cB;
	BYTE *hP;
	pbmih = (PBITMAPINFOHEADER) pbi;
	bits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbmih->biSizeImage);
	if (!bits)
		MessageBox(hwnd, "GlobalAlloc()", "Error", MB_OK);
	if (!GetDIBits(hDC, hBMP, 0, (WORD) pbmih->biHeight, bits, pbi, DIB_RGB_COLORS))
		MessageBox(hwnd, "GetDIBits()", "Error", MB_OK);
	hF.open(file, std::ios::binary);
	if (hF.fail())
		MessageBox(hwnd, "open()", "Error", MB_OK);
	bmfh.bfType = 0x4d42;
	bmfh.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbmih->biSize + pbmih->biClrUsed * sizeof(RGBQUAD) + pbmih->biSizeImage);
	bmfh.bfReserved1 = 0;
	bmfh.bfReserved2 = 0;
	bmfh.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbmih->biSize + pbmih->biClrUsed * sizeof(RGBQUAD);
	hF.write((char*) &bmfh, sizeof(BITMAPFILEHEADER));
	if (hF.fail())
		MessageBox(hwnd, "write() file header", "Error", MB_OK);
	hF.write((char*) pbmih, sizeof(BITMAPINFOHEADER) + pbmih->biClrUsed * sizeof(RGBQUAD));
	if (hF.fail())
		MessageBox(hwnd, "write() info header", "Error", MB_OK);
	total = cB = pbmih->biSizeImage;
	hP = bits;
	hF.write((char*) hP, (int) cB);
	if (hF.fail())
		MessageBox(hwnd, "write() data", "Error", MB_OK);
	hF.close();
	if (hF.fail())
		MessageBox(hwnd, "close()", "Error", MB_OK);
	GlobalFree((HGLOBAL) bits);
}

SaveBmpInfoStruct():

PBITMAPINFO CreateBmpInfoStruct(HWND hwnd, HBITMAP hBMP)
{
	BITMAP BMP;
	PBITMAPINFO pbmi;
	WORD clrBits;
	if (!GetObject(hBMP, sizeof(BITMAP), (LPSTR) &BMP))
		MessageBox(hwnd, "GetObject()", "Error", MB_OK);
	clrBits = (WORD) (BMP.bmPlanes * BMP.bmBitsPixel);
	if (clrBits == 1)
		clrBits = 1;
	else if (clrBits <= 4)
		clrBits = 4;
	else if (clrBits <= 8)
		clrBits = 8;
	else if (clrBits <= 16)
		clrBits = 16;
	else if (clrBits <= 24)
		clrBits = 24;
	else
		clrBits = 32;
	if (clrBits != 24)
		pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * (1<< clrBits));
	else
		pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));
	pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
	pbmi->bmiHeader.biWidth = BMP.bmWidth;
	pbmi->bmiHeader.biHeight = BMP.bmHeight;
	pbmi->bmiHeader.biPlanes = BMP.bmPlanes;
	pbmi->bmiHeader.biBitCount = BMP.bmBitsPixel;
	if (clrBits < 24)
		pbmi->bmiHeader.biClrUsed = (1<< clrBits);
	pbmi->bmiHeader.biCompression = BI_RGB;
	pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * clrBits + 31) & ~31) / 8 * pbmi->bmiHeader.biHeight;
	pbmi->bmiHeader.biClrImportant = 0;
	return pbmi;
}

SaveFileDlg():

BOOL SaveFileDlg(HWND hwnd, LPSTR fileName, LPSTR titleName)
{
	ofn.lStructSize = sizeof(OPENFILENAME);
	ofn.hInstance = GetModuleHandle(NULL);
	ofn.lpstrCustomFilter = NULL;
	ofn.nMaxCustFilter = 0;
	ofn.nFilterIndex = 0;
	ofn.hwndOwner = hwnd;
	ofn.lpstrFile = fileName;
	ofn.lpstrFileTitle = NULL;
	ofn.lpstrTitle = titleName;
	ofn.Flags = OFN_EXPLORER | OFN_OVERWRITEPROMPT;
	ofn.lpstrFilter = "Bitmap Files (*.bmp)\0*.bmp\0\0";
	ofn.lpstrTitle = titleName;
	return GetSaveFileName(&ofn);
}

Let me know if you need to see more code.

Thanks for your help!

[andywestken]

Sorry, but your code is a bit dense to wade though.

I have just built (with a few tweaks...) and run the code in this thread:

Save a bitmap without GetDiBits
http://www.cplusplus.com/forum/beginner/25138/

from a few years ago and it just worked for me; I loaded the resultant .bmp file into Paint.exe fine. (It's about how to eliminate the dependency on GetDIBits call; the code does use it.)

So, if it also works for you, you could compare what it's doing against your own code.

Andy

[jwkNwA7f]

Okay, thank you for replying! I have actually fixed it. It was in a part of the code that I did not post.