C++ Cin.getline无法正确打印，也无法正常工作

在下面的代码中，我试图在文本文件中添加一行信息。目前，我已经尝试了3种不同的选择，但没有一种完全有效。cin.get、cin.getline和cin>>

例如，当我尝试使用cin.getlinename 60时，它将接受信息，但我得到一些打印输出错误，不是编译错误，而是显示错误

1如果我将作业输入为1-Web，它会在cin.getline中接受它，但如果我输入1-Web设计第1部分应用程序并点击enter，我的程序将开始无休止地循环菜单选项，并且不会获取信息

2当我打印文件时，它会打印出来

例：

感谢您的帮助！我可以诚实地说，当我阅读文件时，我已经生疏了。这是我第一次添加到文件中，因此我希望您能解释我为什么会遇到此问题，并可能帮助我解决此问题

下面是我当前的函数，它添加了一行代码和我的主文件代码

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <cstdlib>

using namespace std;


int options = 0;
char name[60];
//string name; //this was when I attempted cin >>
//string assign; // this was when I attempted cin >>
char assign[60];
string date;
string lines;

void addProject () {
cout <<"Enter class name with class number like so: (MCS 220)"<<endl;
    cin.getline(name, 60);
    cin.ignore();
    //cin >> name;
    cout <<endl;
    cout <<"Enter the Project Number < - > then Project title like so:" <<
            " (1 - Web Design Part Application)"<<endl;
    cin.getline(assign, 60);
    cin.ignore();
    //cin >> assign;
    cout <<endl;
    cout << "Enter the due date for assignment like so: (05-12-2015)"<<endl;
    char cMonth[3];
    char cDay [3];
    char cYear[5];

            cin.get(cMonth,3, '-');
            cin.ignore(2, '-');
            cin.get(cDay, 4, '-');
            cin.ignore(2,'/');
            cin.get(cYear, 5);

    //input into file
    ofstream readFile;
    readFile.open("list.txt", std::ios::app);
    readFile << name << ", " << "Project " << assign << ", "
                    << cMonth <<"-"<< cDay <<"-"<< cYear<< endl;
}

//BEGIN MAIN CODE
int main() {

ifstream readFile("list.txt");


if (!readFile){
cout <<"I am sorry but we could not process "<<
     "the file information."<<endl;
}


    menu();
    cin >>options;
    cout <<endl;

    cout <<"In our system we show Class information."<<endl;
    //read and output the file
    while (options != 4)
    {

    //print the listing
    if (options == 3){
    while (getline(readFile, lines)){

    cout << lines<<endl;
       }
    }

    // Add Assignments
    if (options == 1){
            addProject();
     }

    menu();
    cin >>options;
    cout <<endl;

    }//end while
    readFile.close();
}

---

我更新了我的代码。问题是cin.ignore被放置在下一个cin变量的右边

char name[256];

char pnum[20];
char title[256];
string date;
string lines;

void addProject () {
    cout <<"Enter class name with class number like so: (MCS 220)"<<endl;

    cin.ignore(numeric_limits<std::streamsize>::max(), '\n');
    cin.getline(name, 256, '\n');

    //char upperName = toupper(name); /*
          for (char *caps = name; *caps != '\0'; ++caps)
            {
                    *caps = std::tolower(*caps);
                    ++caps;
            }

    cout <<endl;
    cout <<"Enter the Project Number: "<<endl;
    cin.getline(pnum, 20, '\n');
    cin.ignore(numeric_limits<std::streamsize>::max(), '\n');

    cout<<"Enter the Project's title next: "<<endl;
    cin.getline(title, 256, '\n');
    cin.ignore(numeric_limits<std::streamsize>::max(), '\n');
    cout <<endl;

    cout << "Enter the due date for assignment like so: (05-12-2015)"<<endl;
    char cMonth[3];
    char cDay [3];
    char cYear[5];

            cin.get(cMonth,3, '-');
            cin.ignore(2, '-');
            cin.get(cDay, 4, '-');
            cin.ignore(2, '-');
            cin.get(cYear,5);

    //input into file
    ofstream readFile;
    readFile.open("list.txt", std::ios::app);
    readFile << name <<",Project "<< pnum << " - " << title <<
                    ", "<< cMonth <<"-" <<cDay <<"-"<< cYear<< endl;
}

---

首先，您从不检查输入是否失败。知道哪个输入首先失败将对解决您的问题有很大帮助。如果您的意思是要单独排除每个cin，那么我有。如果我注释掉除第一行之外的所有cin.getline，它会接受输入，然后在我的菜单选项中连续循环。第二个cin也是一样。getlineassign。我不是指故障排除。即使在一个似乎可以工作的程序中，在使用输入的值之前，也必须验证输入是否成功。

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <cstdlib>

using namespace std;


int options = 0;
char name[60];
//string name; //this was when I attempted cin >>
//string assign; // this was when I attempted cin >>
char assign[60];
string date;
string lines;

void addProject () {
cout <<"Enter class name with class number like so: (MCS 220)"<<endl;
    cin.getline(name, 60);
    cin.ignore();
    //cin >> name;
    cout <<endl;
    cout <<"Enter the Project Number < - > then Project title like so:" <<
            " (1 - Web Design Part Application)"<<endl;
    cin.getline(assign, 60);
    cin.ignore();
    //cin >> assign;
    cout <<endl;
    cout << "Enter the due date for assignment like so: (05-12-2015)"<<endl;
    char cMonth[3];
    char cDay [3];
    char cYear[5];

            cin.get(cMonth,3, '-');
            cin.ignore(2, '-');
            cin.get(cDay, 4, '-');
            cin.ignore(2,'/');
            cin.get(cYear, 5);

    //input into file
    ofstream readFile;
    readFile.open("list.txt", std::ios::app);
    readFile << name << ", " << "Project " << assign << ", "
                    << cMonth <<"-"<< cDay <<"-"<< cYear<< endl;
}

//BEGIN MAIN CODE
int main() {

ifstream readFile("list.txt");


if (!readFile){
cout <<"I am sorry but we could not process "<<
     "the file information."<<endl;
}


    menu();
    cin >>options;
    cout <<endl;

    cout <<"In our system we show Class information."<<endl;
    //read and output the file
    while (options != 4)
    {

    //print the listing
    if (options == 3){
    while (getline(readFile, lines)){

    cout << lines<<endl;
       }
    }

    // Add Assignments
    if (options == 1){
            addProject();
     }

    menu();
    cin >>options;
    cout <<endl;

    }//end while
    readFile.close();
}

char name[256];

char pnum[20];
char title[256];
string date;
string lines;

void addProject () {
    cout <<"Enter class name with class number like so: (MCS 220)"<<endl;

    cin.ignore(numeric_limits<std::streamsize>::max(), '\n');
    cin.getline(name, 256, '\n');

    //char upperName = toupper(name); /*
          for (char *caps = name; *caps != '\0'; ++caps)
            {
                    *caps = std::tolower(*caps);
                    ++caps;
            }

    cout <<endl;
    cout <<"Enter the Project Number: "<<endl;
    cin.getline(pnum, 20, '\n');
    cin.ignore(numeric_limits<std::streamsize>::max(), '\n');

    cout<<"Enter the Project's title next: "<<endl;
    cin.getline(title, 256, '\n');
    cin.ignore(numeric_limits<std::streamsize>::max(), '\n');
    cout <<endl;

    cout << "Enter the due date for assignment like so: (05-12-2015)"<<endl;
    char cMonth[3];
    char cDay [3];
    char cYear[5];

            cin.get(cMonth,3, '-');
            cin.ignore(2, '-');
            cin.get(cDay, 4, '-');
            cin.ignore(2, '-');
            cin.get(cYear,5);

    //input into file
    ofstream readFile;
    readFile.open("list.txt", std::ios::app);
    readFile << name <<",Project "<< pnum << " - " << title <<
                    ", "<< cMonth <<"-" <<cDay <<"-"<< cYear<< endl;
}