CArchive::WriteClass

Use WriteClass to store the version and class information of a base class during serialization of the derived class.

void WriteClass(
   const CRuntimeClass* pClassRef 
);

Parameters

pClassRef

A pointer to the CRuntimeClass structure that corresponds to the class reference requested.

Remarks

WriteClass writes a reference to the CRuntimeClass for the base class to the CArchive. Use CArchive::ReadClass to retrieve the reference.

WriteClass verifies that the archived class information is compatible with your runtime class. If it is not compatible, WriteClass will throw a CArchiveException.

Your runtime class must use DECLARE_SERIAL and IMPLEMENT_SERIAL; otherwise, WriteClass will throw a CNotSupportedException.

You can use SerializeClass instead of WriteClass, which handles both reading and writing of the class reference.

Example

CFile myFile("myfile.dat", CFile::modeCreate | CFile::modeReadWrite);

// Create a storing archive.
CArchive arStore(&myFile, CArchive::store);

// Store the class CAge in the archive.
arStore.WriteClass( RUNTIME_CLASS(CAge) );

// Close the storing archive.
arStore.Close();

// Create a loading archive.
myFile.SeekToBegin();
CArchive arLoad(&myFile, CArchive::load);

// Load a class from the archive.
CRuntimeClass* pClass = arLoad.ReadClass( );
if (!pClass->IsDerivedFrom(RUNTIME_CLASS(CAge)))
      arLoad.Abort();

See Also

CArchive Overview | Class Members | Hierarchy Chart | CArchive::ReadClass | CArchive::GetObjectSchema | CArchive::SetObjectSchema | CArchive::SerializeClass | CArchiveException | CNotSupportedException | CObList::CObList