Passing Binary Data in COM

Here is the method declared in server IDL:

HRESULT Transfer([in] long cbSize,      
                 [in, size_is(cbSize)] unsigned char cBuffer[])

Here is the client code:

ITargetObj * pITargeObj ;
HRESULT hRC = ::CoCreateInstance(CLSID_TargetObj, 
                                 NULL, 
                                 CLSCTX_SERVER,
                                 IID_ITargetObj, 
                                 (void **)&pITargetObj ) ;
if FAILED( hRC )
{
 AfxMessageBox( "Failed to make target object!" ) ;
 return FALSE ;
}
      
BYTE * pBuffer = (BYTE *)::CoTaskMemAlloc( 15 ) ;
CopyMemory( pBuffer, "HELLO WORLD!!!!", 15 ) ;
pITargetObj->Transfer( 15, pBuffer ) ;
::CoTaskMemFree( pBuffer ) ;
pITargetObj ->Release() ;

Using CBufferVariant

Here is the method declared in server IDL:

HRESULT Transfer([in] VARIANT vData)
      

Here is the server code:

STDMETHODIMP CTargeObj::Transfer(VARIANT Data)
{
 CBufferVariant bvData=Data;
 if(bvData.GetLength()==0)
  return S_OK;
 send(m_nSocketFD,bvData,bvData.GetLength(),0);
 return S_OK;
}

Here is the client code:

#include "BufferVariant.h"

ITargetObj * pITargeObj ;
HRESULT hRC = ::CoCreateInstance(CLSID_TargetObj, 
                                 NULL, 
                                 CLSCTX_SERVER,
                                 IID_ITargetObj, 
                                 (void **)&pITargetObj ) ;
if FAILED( hRC )
{
 AfxMessageBox( "Failed to make target object!" ) ;
 return FALSE ;
}

CBufferVariant bvData;

SomeStruct stData;
bvData.AssignData(&stData,sizeof(SomeStruct));
pITargetObj->Transfer( bvData );

bvData="Hello World!";
bvData+="\n";
pITargetObj->Transfer( bvData );

char buffer[2048];
File1.Read(buffer,2048);
bvData.AssignData(buffer,2048);
File2.Read(buffer,1024);
bvData.AppendData(buffer,1024);
pITargetObj->Transfer( bvData );

pITargetObj->Transfer( CBufferVariant("This is a ANSI string.") ) ;

pITargetObj->Release();

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