void SaveBitmapToFile(HBITMAP hBitmap, char* szfilename)
{HDC hdc;			//设备描述表int ibits;WORD wbitcount;     //当前显示分辨率下每个像素所占字节数//位图中每个像素所占字节数，定义调色板大小，位图中像素字节大小，位图文件大小 ，写入文件字节数DWORD dwpalettesize = 0, dwbmbitssize, dwdibsize, dwwritten;BITMAP bitmap;				//位图属性结构BITMAPFILEHEADER bmfhdr;	//位图文件头结构BITMAPINFOHEADER bi;		//位图信息头结构LPBITMAPINFOHEADER lpbi;	//指向位图信息头结构//定义文件，分配内存句柄，调色板句柄HANDLE fh, hdib, hpal, holdpal = NULL;//计算位图文件每个像素所占字节数hdc = CreateDC("display", NULL, NULL, NULL);ibits = GetDeviceCaps(hdc, BITSPIXEL) * GetDeviceCaps(hdc, PLANES);DeleteDC(hdc);if (ibits <= 1)wbitcount = 1;else if (ibits <= 4)wbitcount = 4;else if (ibits <= 8)wbitcount = 8;else if (ibits <= 16)wbitcount = 16;else if (ibits <= 24)wbitcount = 24;elsewbitcount = 32;//计算调色板大小if (wbitcount <= 8)dwpalettesize = (1 << wbitcount) * sizeof(RGBQUAD);//设置位图信息头结构GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bitmap);bi.biSize = sizeof(BITMAPINFOHEADER);bi.biWidth = bitmap.bmWidth;bi.biHeight = bitmap.bmHeight;bi.biPlanes = 1;bi.biBitCount = wbitcount;bi.biCompression = BI_RGB;bi.biSizeImage = 0;bi.biXPelsPerMeter = 0;bi.biYPelsPerMeter = 0;bi.biClrUsed = 0;bi.biClrImportant = 0;dwbmbitssize = ((bitmap.bmWidth * wbitcount + 31) / 32) * 4 * bitmap.bmHeight;//为位图内容分配内存hdib = GlobalAlloc(GHND, dwbmbitssize + dwpalettesize + sizeof(BITMAPINFOHEADER));lpbi = (LPBITMAPINFOHEADER)GlobalLock(hdib);*lpbi = bi;// 处理调色板 hpal = GetStockObject(DEFAULT_PALETTE);if (hpal){hdc = ::GetDC(NULL);holdpal = SelectPalette(hdc, (HPALETTE)hpal, false);RealizePalette(hdc);}// 获取该调色板下新的像素值GetDIBits(hdc, hBitmap, 0, (UINT)bitmap.bmHeight, (LPSTR)lpbi + sizeof(BITMAPINFOHEADER) + dwpalettesize, (BITMAPINFO*)lpbi, DIB_RGB_COLORS);//恢复调色板 if (holdpal){SelectPalette(hdc, (HPALETTE)holdpal, true);RealizePalette(hdc);::ReleaseDC(NULL, hdc);}//创建位图文件 fh = CreateFile(szfilename, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);if (fh == INVALID_HANDLE_VALUE)return false;// 设置位图文件头bmfhdr.bfType = 0x4d42; // "bm"dwdibsize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) +dwpalettesize + dwbmbitssize;bmfhdr.bfSize = dwdibsize;bmfhdr.bfReserved1 = 0;bmfhdr.bfReserved2 = 0;bmfhdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) +(DWORD)sizeof(BITMAPINFOHEADER) + dwpalettesize;//写入位图文件头WriteFile(fh, (LPSTR)&bmfhdr, sizeof(BITMAPFILEHEADER), &dwwritten, NULL);//写入位图文件其余内容WriteFile(fh, (LPSTR)lpbi, dwdibsize, &dwwritten, NULL);//清除 GlobalUnlock(hdib);GlobalFree(hdib);CloseHandle(fh);
}