Visual Studio 2017无法识别“系统” [英] Visual Studio 2017 not recognizing "system"

问题描述

我最近从Visual Studio 2015升级到Visual Studio 2017. 当我打开我在2015年编写的程序时，系统和tolower被标记为未定义，我无法获得编译代码。

I recently upgraded from Visual Studio 2015 to Visual Studio 2017.  When I opened a program that I had written in 2015, system and tolower were flagged as undefined and I could not get the code to compile.

#include< iostream>

#include< cstdlib>

#include< cctype> ; $
#include< vector>

#include< iomanip>

使用命名空间std;



#include" CashRegister.h"

#include" Inventory.h"

#include" CustomerDB.h"

#include" Customer.h"

#include" Report.h"

#include" InventoryBook.h"



const string INVENTORY_FILENAME =" inventory.dat";



void cashRegisterMenu（CashRegister& cr，Inventory& inv）;

void customerMenu（CustomerDB& cdb）;

void inventoryMenu（Inventory& inv）;

void reportMenu（Report& rep，Inventory& inv ，CustomerDB& cdb）;
$
void displayBookInfo（const InventoryBook * book）;
$
void displayCustomerInfo（Customer customer）;

InventoryBook makeBook（）;

InventoryBook editBook（const InventoryBook * book）;

Customer makeCustomer（）;



int main（）

{

    字符选择;

     //浮动费用;

     CashRegister cr;

    库存inv（INVENTORY_FILENAME）;

    报告代表;

     CustomerDB cdb;



     do

     {

   &NBSP;&NBSP;&NBSP; &NBSP;系统（QUOT; CLS"）;&NBSP; //未定期

   &NBSP;&NBSP;&NBSP;   cout<< "欢迎使用Serendipity书商POS软件系统"
$
   &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;<< endl<<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "选项：" << endl<<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "R - 收银机" <<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "我 - 库存" <<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "C - 客户" <<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "H - 报告" <<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "Q - 退出计划" << endl<<结束;

   &NBSP;&NBSP;&NBSP;   cout<< "输入选项：";
$


   &NBSP;&NBSP;&NBSP;   choice = tolower（cin.get（））; //未定期

#include <iostream>
#include <cstdlib>
#include <cctype>
#include <vector>
#include <iomanip>
using namespace std;

#include "CashRegister.h"
#include "Inventory.h"
#include "CustomerDB.h"
#include "Customer.h"
#include "Report.h"
#include "InventoryBook.h"

const string INVENTORY_FILENAME = "inventory.dat";

void cashRegisterMenu(CashRegister& cr, Inventory& inv);
void customerMenu(CustomerDB& cdb);
void inventoryMenu(Inventory& inv);
void reportMenu(Report& rep, Inventory& inv, CustomerDB& cdb);
void displayBookInfo(const InventoryBook* book);
void displayCustomerInfo(Customer customer);
InventoryBook makeBook();
InventoryBook editBook(const InventoryBook* book);
Customer makeCustomer();

int main()
{
    char choice;
    //float cost;
    CashRegister cr;
    Inventory inv(INVENTORY_FILENAME);
    Report rep;
    CustomerDB cdb;

    do
    {
        system("CLS");  // UNDEFINED
        cout << "Welcome to the Serendipity Booksellers POS Software System"
            << endl << endl;
        cout << "Options:" << endl << endl;
        cout << "R - Cash Register" << endl;
        cout << "I - Inventory" << endl;
        cout << "C - Customer" << endl;
        cout << "H - Report" << endl;
        cout << "Q - Quit Program" << endl << endl;
        cout << "Enter option: ";

        choice = tolower(cin.get()); // UNDEFINED

我最终创建了一个新项目并搬家所有文件都进入了新项目。当我这样做时，一切都在新项目中起作用，但所有代码都完全相同。我真的不想为2017年之前在VS的某个版本
中编写的每个程序执行此操作。任何人都对可能发生的事情有任何想法，如何在不创建新的情况下纠正它项目和复制文件？

I ended up creating a new project and moving all the files into the new project. When I did this, everything worked in the new project but all the code is exactly the same. I really do not want to have to do this for every program I had written in some version of VS prior to 2017. Any one have any ideas of what might have happened and how I could have corrected it without creating a new project and copying the files over?

推荐答案

system 函数需要< ;文件stdlib.h>或< process.h>头。尝试在旧项目中添加
'#include< stdlib.h>'。

The system function requires the <stdlib.h> or <process.h> header. Try adding ‘#include <stdlib.h>’ in your old project.

也许在新项目中，标题是在"stdafx.h"文件中指定的，这是适合这类事情的地方。

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