作者：未知 来源：月光软件站 加入时间：2005-2-28　月光软件站

//  你的CSimpleObj类看起来这样子的
class CSimpleObj : public CObject
{
  DECLARE_SERIAL( CSimpleObj )
public:
  // constructor and destructor
  CSimpleObj();
  virtual ~CSimpleObj();
  // 设置内部的字符串
  void SetString( CString csData );
  // 用于串行化你的数据
  virtual void Serialize(CArchive& ar);
  // 显示数据
  void Show();
private:
  CString m_strData;//这里定义一个字符串对象
};

// Write this object to an archive
void CSimpleObj::Serialize(CArchive& ar)
{
  CObject::Serialize( ar );

  if (ar.IsLoading())
  {
  // extract data from archive
    ar >> m_strData;
  }
  else
  {
    // store data into archive
    ar << m_strData;
  }
}

// Method to display data in this object
void CSimpleObj::Show()
{
  AfxMessageBox(m_strData);
}

// save a string in data member
void CSimpleObj::SetString(CString csData)
{
  m_strData = csData;
}

class CBlob
{
public:
  CBlob() {};
  virtual ~CBlob() {};

  // Extract data from a CObject and load it into a SAFEARRAY.
  SAFEARRAY* Load( CObject *pObj );
  // Re-create an object from a SAFEARRAY
  BOOL Expand( CObject * &pObj, SAFEARRAY *pVar );
private:
};

// Extract data from a CObject and use it to create a SAFEARRAY.
SAFEARRAY* CBlob::Load( CObject *pObj)
{
  CMemFile memfile;      // memory file

  // define the flag that tells the archive whether it should 
  // load or store
  long lMode = CArchive::store | CArchive::bNoFlushOnDelete;
  // create the archive using the memory file
  CArchive ar(&memfile, lMode );

  // m_pDocument is not used
  ar.m_pDocument = NULL;
  // serialize the object into the archive
  ar.WriteObject(pObj);
  // close the archive -- the data is now stored in memfile
  ar.Close();

  // get the length (in bytes) of the memory file
  long llen = memfile.GetLength();

  // detach the buffer and close the file
  unsigned char *pMemData = memfile.Detach();

  // set up safearray
  SAFEARRAY *psa;

  // create a safe array to store the stream data
  psa = SafeArrayCreateVector( VT_UI1, 0, llen );

  // pointers to byte arrays
  unsigned char *pData = NULL;

  // get a pointer to the safe array. Locks the array.
  SafeArrayAccessData( psa, (void**)&pData );

  // copy the memory file into the safearray
  memcpy( pData, pMemData, llen );

  // clean up buffer
  delete pMemData;

  // unlock access to safearray
  SafeArrayUnaccessData(psa);

  // return a pointer to a SAFEARRAY allocated here
  return psa;
}

// Re-create an object from a SAFEARRAY
BOOL CBlob::Expand(CObject * &rpObj, SAFEARRAY *psa)
{
  CMemFile memfile;          // memory file for de-serailze
  long lLength;              // number of bytes
  char *pBuffer;             // buffer pointer

  // lock access to array data
  SafeArrayAccessData( psa, (void**)&pBuffer );

  // get number of elements in array. This is the number of bytes
  lLength = psa->rgsabound->cElements;

  // attach the buffer to the memory file
  memfile.Attach((unsigned char*)pBuffer, lLength);

  // start at beginning of buffer
  memfile.SeekToBegin();

  // create an archive with the attached memory file
  CArchive ar(&memfile, CArchive::load | CArchive::bNoFlushOnDelete);

  // document pointer is not used
  ar.m_pDocument = NULL;

  // inflate the object and get the pointer
  rpObj = ar.ReadObject(0);

  // close the archive
  ar.Close();

  // Note: pBuffer is freed when the SAFEARRAY is destroyed
  // Detach the buffer and close the file
  pBuffer = (char*) memfile.Detach();

  // release the safearray buffer
  SafeArrayUnaccessData( psa );

  return TRUE;
}

最后,我们做一个带有2个按钮的对话框应用程序, 2个按钮的响应方法是:
void CClientDlg::OnOK()
{
// create COM smart pointer from CLSID string
  try
  {
    IBolbDataPtr pI( "Server.BolbData.1" );
    SAFEARRAY *psa ;

    // Get the safearray from the server
    pI->GetArray( &psa );

    // create a pointer to an object
    CSimpleObj *dummy=NULL;

    // blob object to expand
    CBlob blob;

    // use the blob to expand the safearray into an object
    blob.Expand( (CObject *&)dummy, psa );
    // call a method on the object to test it
    dummy->Show();

    // delete the object
    delete dummy;
  }
  // Handle any COM exceptions from smart pointers
  catch (_com_error e)
  {
    // display the message string from the error
    AfxMessageBox( e.ErrorMessage() );
  }
}

void CClientDlg::OnLoad()
{
  try
  {
    // create smart pointer from CLSID string
    IBolbDataPtr pI( "Server.BolbData.1" );
    SAFEARRAY *psa ;

    // create object to send to server
    CSimpleObj *pMyOb = new CSimpleObj();

    // set the string data
    pMyOb->SetString( "The client sent a SAFEARRAY!" );

    // create blob to serialize object
    CBlob blob;

    // load the object into the blob
    psa = blob.Load( pMyOb );

    // delete the object
    delete pMyOb;

    pI->SetArray( psa );

  }
  // Handle any COM exceptions from smart pointers
  catch (_com_error e)
  {
    // display the message string from the error
    AfxMessageBox( e.ErrorMessage() );
  }
}
这个例子里涵盖的内容比较多,包括了如何使用串行化,如何使用安全数组,如何通过接口传递C++对象.

作者原贴在这里:
http://www.codeguru.com/Cpp/COM-Tech/atl/atl/article.php/c3587/

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