Get Ready to Unleash the Power of UCanCode .NET

Introduction

A more easy to save your memory dc to a (DIB) bitmap file(*.bmp), sometimes we don't need to bitblt our map to windows to display. this is a new way you can try.

Using the code

Only a function we needed here.It's very hard to post whole project file here to discuss. so i suppose the reader have some basic ideal about GDI programming. Pass two parameters into the function , you may need CreateCompatibleBitmap to init your second parameter.

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HBITMAP CreateCompatibleBitmap(
  HDC hdc,        // handle to device context
  int nWidth,     // width of bitmap, in pixels
  int nHeight     // height of bitmap, in pixels
);

After you call this function sucessfully, it will generate a new bitmap named "temp.bmp" under your partation C root folder.

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SaveMemDCToBitmapNoPalete(HDC p_hMemDC,HBITMAP p_hBitmap)
{
 HDC hMemDC = p_hMemDC;
 HBITMAP hBitmap = p_hBitmap;
 int   wBitCount = 32;
 
 BITMAP   Bitmap;  
 BITMAPFILEHEADER   bmfHdr;    
 BITMAPINFOHEADER   bi;
 
 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; 
 
 DWORD dwBmBitsSize = ((Bitmap.bmWidth * wBitCount + 31) / 32) * 4 * Bitmap.bmHeight; 
 
 HANDLE hDib = GlobalAlloc(GHND,dwBmBitsSize+sizeof(BITMAPINFOHEADER)); 
 LPBITMAPINFOHEADER lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);    
 *lpbi = bi;
 
 GetDIBits(hMemDC, hBitmap, 0, (UINT)Bitmap.bmHeight,  
  (LPSTR)lpbi + sizeof(BITMAPINFOHEADER), (BITMAPINFO *)lpbi, DIB_RGB_COLORS);    
 
 HANDLE fh = CreateFile("c:\\temp.bmp",GENERIC_WRITE,0,NULL,CREATE_ALWAYS,
  FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN,NULL);   
 ASSERT(fh != INVALID_HANDLE_VALUE);
 
 DWORD dwDIBSize   =   sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + dwBmBitsSize;
 
 bmfHdr.bfType = 0x4D42;    
 bmfHdr.bfSize = dwDIBSize;  
 bmfHdr.bfReserved1 = 0;    
 bmfHdr.bfReserved2 = 0;    
 bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER);    
 
 DWORD dwWritten;
 
 WriteFile(fh,   (LPSTR)&bmfHdr,   sizeof(BITMAPFILEHEADER),   &dwWritten,   NULL);    
 WriteFile(fh, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);    
 GlobalUnlock(hDib);    
 GlobalFree(hDib);    
 CloseHandle(fh);
 return TRUE;
}