为什么我的输入在这个C++程序中如此混乱？

Question

我试图为Linux制作一个命令行邮件应用程序（虽然我是在Xcode上开发的，因为虚拟机对我的电脑来说很耗电）。我在主菜单中有两个选项（用户输入数字选择）。我在每次输入后都会使用这个选项，无论是简单的can还是get line(can, stringName)。

void clearCin() {
    cin.clear();
    cin.ignore(INT_MAX, '\n');
}

这就是为什么我很困惑，我的输入会出现各种奇怪的行为。这是我的代码和一个输出示例（最后的函数只是一个for循环，做cost << endl;）。

代码

bool stdEmail() {

    string to, cc, bcc, subject, message;

    cout << "When entering email addresses, seperate multiple email addresses with a space";
    endl(2);

    cout << "To: ";
    getline(cin, to);
    clearCin();

    cout << "cc: ";
    getline(cin, cc);
    clearCin();

    cout << "bcc: ";
    getline(cin, bcc);
    clearCin();
    endl(1);

    cout << "Subject: ";
    getline(cin, subject);
    clearCin();
    endl(1);

    cout << "Now enter your message, when you're finished, type a period on a new line";
    endl(2);

    ofstream file;
    file.open("newMessage.txt", fstream::trunc);

    bool repeat = true;

    while (repeat) {
        getline(cin, message);
        clearCin();
        if (message == ".") {
            repeat = false;
        } else {
            file << message << endl;
        }
    }

    file.close();
    return true;
}

产量

--------------------------------------------------
Welcome to mark's Multi-Mail program

Main menu:
--------------------------------------------------
1. Send personalized emails to multiple recipients
2. Send a standard email
3. Exit the program
--------------------------------------------------
2

When entering email addresses, seperate multiple email addresses with a space

To: [email protected] [email protected]

cc: [email protected]

bcc: 


Subject: Thanks for your help!


Now enter your message, when you're finished, type a period on a new line

Here is a sample message
.

Now I am trying to get it out of taking the message which should have happened when I typed a .


.


Program ending Have a Nice Day

Program ended with exit code: 0

下面是newMessage.txt中显示的内容。

以下是一个示例信息

Answer 1

cin.ignore(INT_MAX, '\n'); 丢弃换行，getline在读取换行时完成，所以你必须在输入信息后按两次回车键才能让getline读取信息，你必须在输入'.'后按两次回车键才能结束循环。