C / C++ / MFC

void COperatorDlg::OnBnClickedWriteBtn()   
{   
 // TODO: Add your control notification handler code here   
 CMap<int, int, OperatorDetails, OperatorDetails> newOperMap;   
  
 DbOperations db;   
 newOperMap.SetAt(1, OperatorDetails(1, _T("One")));   
 newOperMap.SetAt(2, OperatorDetails(2, _T("Two")));   
 db.WriteOperators(newOperMap);   
}   
  
  
void COperatorDlg::OnBnClickedReadBtn()   
{   
 // TODO: Add your control notification handler code here   
 CMap<int, int, OperatorDetails, OperatorDetails>* existOperMap;   
  
 DbOperations db;   
 existOperMap = db.ReadOperators();   
 CString s = _T("Read Operators : ");   
 s.Format(_T("%s %d"), s, existOperMap->GetCount());   
 AfxMessageBox(s);   
}   
  
  
DbOperations::DbOperations()   
{   
 operMap = new CMap<int, int, OperatorDetails, OperatorDetails>(10);   
 deptMap = new CMap<int, int, DeptDetails, DeptDetails>(10);   
}   
  
  
// Write Operators to the file   
void DbOperations::WriteOperators(CMap<int, int, OperatorDetails, OperatorDetails> &opdtMap) {   
 HANDLE hFile = CreateFile(OPER_FILE,   
      GENERIC_WRITE, FILE_SHARE_WRITE,   
         NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);   
  
 if (hFile == INVALID_HANDLE_VALUE)   
  AfxMessageBox(_T("Error OPeniong File"));   
 else {   
  CFile myfile(hFile);   
  int key;   
  OperatorDetails od;   
  
  CArchive ar(&myfile, CArchive::store);   
  
  for (POSITION pos = opdtMap.GetStartPosition(); pos != NULL;) {   
   opdtMap.GetNextAssoc(pos, key, od );    
   ar.WriteObject(&od);   
   od.~OperatorDetails();   
  }   
     
  od.~OperatorDetails();   
  ar.Close();   
  myfile.Close();   
 }   
  
 return;   
}   
  
// Read Operators from the file   
CMap<int, int, OperatorDetails, OperatorDetails>* DbOperations::ReadOperators()   
{   
 int count =0;   
 if(operMap->IsEmpty() == false)   
  operMap->RemoveAll();   
  
 HANDLE hFile = CreateFile(OPER_FILE,   
      GENERIC_READ, FILE_SHARE_READ,   
         NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);   
  
    
 if (hFile == INVALID_HANDLE_VALUE)   
  AfxMessageBox(_T("Error OPening File"));   
 else {   
  CFile myfile(hFile);   
  OperatorDetails* od;   
  OperatorDetails odObj;   
  
  // Start from start of the file   
  myfile.SeekToBegin();   
  CArchive ar(&myfile, CArchive::load);   
  
  
  while (true) {   
   od = (OperatorDetails*) ar.ReadObject( RUNTIME_CLASS(OperatorDetails) );    //************* I got to trap to stop   
   if (od == NULL)   
    break;   
      
   odObj.SetOperatorNo(od->GetOperatorNo());   
   odObj.SetOperName(od->GetOperName());   
//   ASSERT(odObj == *od);   
  
   count++;   
//     while ( (ar.Read(&dd, sizeof(dd))) != 0) {   
   operMap->SetAt(odObj.GetOperatorNo(), odObj);   
  }   
        
  CString s;   
  s.Format(_T("%d %s %d"), operMap->GetCount(), _T(" Count = "), count);   
  AfxMessageBox(s);   
  
  odObj.~OperatorDetails();   
  od->~OperatorDetails();   
  delete od;   
  myfile.Close();   
  myfile.~CFile();   
 }   
    
 return operMap;   
}