從文件存儲故障，需要所有行被傳輸但最後

Question

我試圖發送文件數據到一個istream變量，停止讀取最後一行之前，離開之前，存儲。有沒有簡單的方法來實現它？停止角色或類似的東西？

istream& TransactionList::getDataFromStream(istream& is) { 
    //read in (unformatted) transaction list from input stream 
    Transaction aTransaction; 
    is >> aTransaction; //read first transaction 
    while (is != 0)  
    {  ^^^^^^^ 
     listOfTransactions_.addAtEnd(aTransaction); //add transaction to list of transactions 
     is >> aTransaction; //read in next transaction 
    } 
    return is; 
} 

Answer 1

簡單。檢查它不是最後一個。你可能想檢查EOF。

istream& TransactionList::getDataFromStream(istream& is) { 
    //read in (unformatted) transaction list from input stream 
    Transaction aTransaction; 
    Transaction aNextTransaction; 
    is >> aTransaction; //read first transaction 
    while (!is.eof())  
    {  ^^^^^^^ 
     aTransaction = aNextTransaction; 
     is >> aNextTransaction; //read in next transaction 
     // last read didn't set EOF, so its not the last line. Add the previous. 
     if (!is.eof()) 
      listOfTransactions_.addAtEnd(aTransaction); //add transaction to list of transactions 
    } 
    return is; 
}