示例#1
0
// update balance in record
void updateRecord( fstream &updateFile )
{
   // obtain number of account to update
   int accountNumber = getAccount( "Enter account to update" );

   // move file-position pointer to correct record in file
   updateFile.seekg( ( accountNumber - 1 ) * sizeof( ClientData ) );

   // read first record from file
   ClientData client;
   updateFile.read( reinterpret_cast< char * >( &client ), 
      sizeof( ClientData ) );

   // update record
   if ( client.getAccountNumber() != 0 ) 
   {
      outputLine( cout, client ); // display the record

      // request user to specify transaction
      cout << "\nEnter charge (+) or payment (-): ";
      double transaction; // charge or payment
      cin >> transaction;

      // update record balance
      double oldBalance = client.getBalance();
      client.setBalance( oldBalance + transaction );
      outputLine( cout, client ); // display the record

      // move file-position pointer to correct record in file
      updateFile.seekp( ( accountNumber - 1 ) * sizeof( ClientData ) );

      // write updated record over old record in file
      updateFile.write( reinterpret_cast< const char * >( &client ), 
         sizeof( ClientData ) );
   } // end if
示例#2
0
// display single record
void outputLine( ostream &output, const ClientData &record )
{
   output << left << setw( 10 ) << record.getAccountNumber()
      << setw( 16 ) << record.getLastName()
      << setw( 11 ) << record.getFirstName()
      << setw( 10 ) << setprecision( 2 ) << right << fixed 
      << showpoint << record.getBalance() << endl;
} // end function outputLine