How Can I Save a Bitmap To Memory

How Can I Save a Bitmap To Memory

Below is a code sample how to use BCSaveImageToBuffer:

#include "windowsx.h"

// after BCCreate(..)

// generate image in buffer
LPBYTE lpBuffer;
eCode = BCSaveImageToBuffer (pBarCode, &lpBuffer, eIMBmp, nWidth, nHeight, 96.0, 96.0);

if (eCode == ErrOk)
{
  // lock buffer before reading
  if (GlobalLockPtr(lpBuffer))
  {
    // retrieve size of buffer
    int nSize = GlobalSize((HGLOBAL)GlobalHandle(lpBuffer));

    // process buffer
    for (int i=0; i< nSize; i++)
    {
      BYTE byte = (static_cast<LPBYTE> (lpBuffer))[i];
      // ...
    }

    // unlock after reading (required)
    GlobalUnlockPtr(lpBuffer);
  }

  // free memory (required)
  GlobalFreePtr(lpBuffer);
}

Alternative API Functions

ERRCODE BCBitmapToMemory (t_BarCode *pBarCode, VOID *pHandle, LPCSTR pszFormat, 
INT *pnSize, LPCRECT pRect)

Writes barcode in an image format to memory block. Does not require global heap memory (=is faster) but does not render the HRT.

Even if you use an escape sequence for binary data the encoder will use code page conversion (example: \x88 leads to a different value in Data Matrix as desired).

Solution:

• Switch off code page conversion (use encoding mode LowByte)
• Force binary encoding mode if available (see PDF417 encoding mode, Data Matrix EnforceBinaryEncoding)