Serialization is not just storing or retrieving information to and from disk filesystem. It is generic to any file stream class. CArchive class is used to make it generic to any stream.

Serialization routine does not directly deal with CFile. It uses CArchive object instead of CFile. CArchive class decouples the file object from Serialize() routine.

Serialization routine

Serialize routine has this prototype.

void Serialize(CArchive& ar)

Let us look into a simple example. Here we declared a class called CStudent to store and retrieve fields of a student. It contains standard, enrollment number, name, marks and age. We are saving or restoring these members Serialize routine.

class CStudent : public CObject
public :

  WORD    m_wStd;
  WORD    m_wRoll;
  CString m_sName;
  double  m_dMarks;
  WORD    m_wAge;

public :
  void Serialize(CArchive& ar);


IMPLEMENT_SERIAL(CStudent, CObject, 0)

/* Main Serialize routine */
void CStudent::Serialize(CArchive& ar)

  if( ar.IsStoring() ) {
    /* Serialize STD, ROLL, NAME, MARKs, AGE to file */
    ar << m_wStd << m_wRoll << m_sName << m_dMarks << m_wAge;
  } else {
    /* Read STD, ROLL, NAME, MARKs, AGE from file */
    ar >> m_wStd >> m_wRoll >> m_sName >> m_dMarks >> m_wAge;


CArchive and Serialization

Serialization routine uses CArchive object and CArchive is constructed from a generic file stream. This is to support any type of stream classes in Serialize routine and make it independent of file stream. Thus Serialize is not limited to disk/storage files. It can be socket file to Serialize in network stream or serial stream file transmitted in serial port.

/* Serialize routine for data saving */
void OnSave() 

  CXXXFile file;
  /* Open stream for writing */
  file.Open(< file >, < write mode >);
  /* pass file to CArchive constructor */
  CArchive ar(&file, CArchive::store);

/* Serialize routine for data retrieving */
void OnOpen() 
  CXXXFile file;
  /* Open stream for writing */
  file.Open(< file >, < read mode >);
  /* pass file to CArchive constructor */
  CArchive ar(&file, CArchive::load);

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