在我的代码中的大多数“按回车键继续..”操作中，似乎让我按两次回车键才能继续。我不确定是什么导致它显示两次而不是一次。这是问题的输出示例：
===============================
Main Menu
===============================
1. Register for vaccine
2. View Profile details
3. Sign Out
输入您的选择：3 正在退出... 按 Enter 继续...按 Enter 继续...
我尝试删除
cin.get()cin.ignore();#include<iostream>
#include<string>
#include<cstdlib>
#include<vector>
#include<limits>
#include<iomanip>
#include<fstream>
#include<conio.h>
using namespace std;
class User {
public:
string name, username, password, nationality, add, dob;
int age, icNumber, ph;
char sex;
bool registeredForVaccine;
User() : registeredForVaccine(false) {}
void displayProfile() const {
cout << " Name: " << name << "\n Age: " << age << "\n IC Number: " << icNumber
<< "\n Registered for Vaccine: " << (registeredForVaccine ? "YES" : "NO") << "\n";
}
void saveToFile() const {
ofstream file("users.txt", ios::app);
if (file.is_open()) {
file << username << " " << password << " "
<< age << " " << dob << " " << sex << " "
<< icNumber << " " << add << " "
<< nationality << " " << ph << " "
<< registeredForVaccine << "\n";
file.close();
}
}
static bool loadFromFile(const string& username, const string& password, User& user) {
ifstream file("users.txt");
string line;
while (getline(file, line)) {
istringstream iss(line);
if (iss >> user.username >> user.password &&
user.username == username && user.password == password) {
iss >> user.age >> user.dob >> user.sex
>> user.icNumber >> user.add
>> user.nationality >> user.ph
>> user.registeredForVaccine;
file.close();
return true; // User found in file
}
}
file.close();
return false; // User not found in file
}
};
class VaccineRegistrationSystem {
private:
vector<User> users; // Store multiple user accounts
User currentUser;
public:
void loginPage(const User& user = User()) {
cout << " Enter username: ";
cin >> currentUser.username;
if (currentUser.username.empty()) {
return; // Go back to the login/sign-up page
}
cout << " Enter password: ";
// Disable echoing
char ch;
string password;
while ((ch = _getch()) != '\r') { // Enter key pressed
if (ch == '\b') { // Backspace key pressed
if (!password.empty()) {
cout << "\b \b"; // Move back and overwrite with space
password.pop_back(); // Remove last character
}
} else {
cout << '*'; // Print an asterisk
password.push_back(ch); // Add character to the password
}
}
currentUser.password = password;
// Enable echoing
cout << endl;
// Check user information from file
User loadedUser;
if (User::loadFromFile(currentUser.username, currentUser.password, currentUser)) {
cout << " Login successful!\n";
mainMenu();
} else {
cout << " Invalid username or password. Please try again.\n";
cout << " Press Enter to continue...";
cin.ignore(numeric_limits<streamsize>::max(), '\n');
cin.get();
loginPage(); // Show login page again if login fails
}
}
void signUpPage() {
system("cls");
cout << " Enter Name: ";
cin.ignore(); // Clear newline character from the buffer
getline(cin, currentUser.name);
cout << " Enter date of birth (xx-xx-xxxx): ";
cin >> currentUser.dob;
cout << " Enter IC number: ";
cin >> currentUser.icNumber;
cout << " Enter a new username: ";
cin >> currentUser.username;
cout << " Enter a new password: ";
cin >> currentUser.password;
currentUser.registeredForVaccine = true; // Assuming registration is successful by default
users.push_back(currentUser); // Add the new user to the vector
// Save user information to file
currentUser.saveToFile();
cout << " Registration successful!\n";
mainMenu();
}
void forgotPasswordUsernamePage() {
system("cls");
cout << " Enter IC number: ";
cin >> currentUser.icNumber;
bool foundUser = false;
for (const User& user : users) {
if (user.icNumber == currentUser.icNumber) {
foundUser = true;
cout << " Found username: " << user.username << "\n and password: " << user.password << "\n";
break;
}
}
if (!foundUser) {
cout << " IC number is not registered. Press enter again to return to login page...\n";
}
}
void mainMenu() {
int choice;
do {
system("cls");
cout << setw(50) << " ===============================\n";
cout << setw(40) << " Main Menu\n";
cout << setw(50) << " ===============================\n";
cout << setw(43) << " 1. Register for vaccine\n";
cout << setw(43) << " 2. View Profile details\n";
cout << setw(31) << " 3. Sign Out\n";
cout << setw(5) << "\n Enter your choice: ";
cin >> choice;
switch (choice) {
case 1:
registerForVaccine();
break;
case 2:
viewProfileDetails();
break;
case 3:
cout << " Signing out...\n";
break;
default:
cout << " Invalid choice. Please try again.\n";
}
// Pause for the user to see the output
cout << " Press Enter to continue...";
} while (choice != 3); // Continue the loop until the user chooses to sign out
}
void registerForVaccine() {
system("cls");
cout << " =============================================================\n";
cout << " Register for vaccine\n";
cout << " =============================================================\n";
cout << " Enter full name : ";
// Clear newline character from the buffer
cin.ignore();
// Read the full name
getline(cin, currentUser.name);
cout << " Enter age : ";
cin >> currentUser.age;
// Clear the newline character from the buffer after reading the age
cin.ignore();
cout << " Enter date of birth (xx-xx-xxxx): ";
cin >> currentUser.dob;
cout << " Enter sex (F/M) : ";
cin >> currentUser.sex;
cout << " Enter IC Number : ";
cin >> currentUser.icNumber;
cout << " Enter address : ";
cin >> currentUser.add;
cout << " Enter Nationality : ";
cin >> currentUser.nationality;
cout << " Enter phone number : ";
cin >> currentUser.ph;
// Check eligibility based on age
if (currentUser.age >= 18) {
currentUser.registeredForVaccine = true;
// Save user information to file after registration
currentUser.saveToFile();
// Display registration successful message
cout << "\n Registration successful!\n";
} else {
currentUser.registeredForVaccine = false;
// Display ineligibility message
cout << "\n Registration unsuccessful. Eligibility for vaccine is 18 years and above.\n";
}
// Pause for the user to see the output
cout << "\n Press Enter to continue...";
cin.ignore();
cin.get();
}
void viewProfileDetails() {
system("cls");
cout << " ===============================\n";
cout << " View Profile details\n";
cout << " ===============================\n";
if (currentUser.registeredForVaccine) {
cout << " Full Name : " << currentUser.name << "\n";
cout << " Age : " << currentUser.age << "\n";
cout << " Date of birth : " << currentUser.dob << "\n";
cout << " Sex : " << currentUser.sex << "\n";
cout << " IC Number : " << currentUser.icNumber << "\n";
cout << " Address : " << currentUser.add << "\n";
cout << " Nationality : " << currentUser.nationality << "\n";
cout << " Phone Number : " << currentUser.ph << "\n";
} else {
cout << " User has not registered for the vaccine. Please register first.\n";
}
// Pause for the user to see the output
cout << "\n Press Enter to continue...";
cin.ignore();
cin.get();
}
};
int main() {
VaccineRegistrationSystem registrationSystem;
do {
system("cls"); // Use "cls" for Windows
cout << setw(50) << " ===============================\n";
cout << setw(41) << " Login/Sign up\n";
cout << setw(50) << " ===============================\n";
cout << setw(29) << " 1. Login\n";
cout << setw(31) << " 2. Sign Up\n";
cout << setw(48) << " 3. Forgot password/username\n";
cout << setw(28) << " 4. Exit\n";
cout << setw(39) << "\n Enter your choice: ";
int choice;
cin >> choice;
switch (choice) {
case 1:
registrationSystem.loginPage();
break;
case 2:
registrationSystem.signUpPage();
break;
case 3:
cout << " Exiting program...\n";
break;
case 4:
cout << " Exiting program.\n";
return 0; // Exit the program
default:
cout << " Invalid choice. Please try again.\n";
}
// Pause for the user to see the output
cout << " Press Enter to continue...";
cin.ignore();
cin.get();
} while (true);
return 0;
}
在你的代码中
cin.ignore();
cin.get();
调用
ignoreget所以你需要输入两个字符（任意字符，不仅仅是换行符）程序才能继续。