C / C++ / MFC

DWORD CALLBACK _LoadRtfCallback(
DWORD dwCookie, // (in) pointer to the string
LPBYTE pbBuff, // (in) pointer to the destination buffer
LONG cb, // (in) size in bytes of the destination buffer
LONG FAR *pcb // (out) number of bytes transfered
)

void CRichEgView::OnReadin() 
{
	CString sWriteText; //Where the text will be streamed from
	sWriteText="Rich text is shown here in sample project";

	// This is hard-coded for example purposes. It is likely this would
	// be read from file or another source.
	EDITSTREAM es;
	es.dwCookie = (DWORD)&sWriteText; // Pass a pointer to the CString to the callback function
	es.pfnCallback = MEditStreamInCallback; // Specify the pointer to the callback function

	GetRichEditCtrl().StreamIn(SF_RTF,es); // Perform the streaming
}

void CTrain1View::OnReadin() 
{
	CString sWriteText; //Where the text will be streamed from
	sWriteText="Rich text is shown here in sample project";

	// This is hard-coded for example purposes. It is likely this would
	// be read from file or another source.
	EDITSTREAM es;
	es.dwCookie = (DWORD)&sWriteText; // Pass a pointer to the CString to the callback function
	es.pfnCallback = _LoadRtfCallback; // Specify the pointer to the callback function

	m_richedit.StreamIn(SF_RTF,es); // Perform the streaming
}

DWORD CALLBACK _LoadRtfCallback(
   DWORD dwCookie,      // (in) pointer to the string
   LPBYTE pbBuff,       // (in) pointer to the destination buffer
   LONG cb,             // (in) size in bytes of the destination buffer
   LONG FAR *pcb        // (out) number of bytes transfered
   )
{
   LPCTSTR pszMsg = (LPCTSTR)dwCookie;

   // number of bytes to copy
   *pcb = _tcslen( pszMsg ) * sizeof(TCHAR);

   // limiting it up to the buffer's size
   if( *pcb > cb )
      *pcb = cb;

   // copying the string to the buffer
   memcpy( pbBuff, pszMsg, *pcb );

   // advancing to the end of the string
   pszMsg += *pcb / sizeof(TCHAR);

   // if it's the end of the string, returns NULL;
   // otherwise, returns a pointer to the next char to transfer as the cookie
   return ( *pszMsg != '\0' ) ? (DWORD)pszMsg : NULL;
}