C++检测回车键问题：掩码用户输入时回车键仍被识别为字符

Hey there! Let's sort out this password masking issue you're facing. The main problem here is that when you press Enter in a Windows console, _getch() returns '\r' (carriage return) instead of '\n' (newline). Your current code checks for '\n', which never matches, so the Enter key gets added to your password string and an extra * is printed instead of breaking the loop.

Here's the corrected, improved version of your code, with explanations:

#include <iostream>
#include <string>  // Required for std::string
#include <conio.h>

int main() {
    std::cout << "Password: ";
    std::string passwd;  // Declare the password storage variable (missing in your original code)
    char c;

    // Mask password input loop
    while ((c = _getch())) {
        // Catch the Enter key (Windows uses '\r' for physical Enter presses)
        if (c == '\r') {
            break;
        }
        // Optional: Handle backspace to let users correct their input
        else if (c == '\b') {
            if (!passwd.empty()) {
                passwd.pop_back();  // Remove the last character from the password
                // Visually erase the last *: backspace, overwrite with space, backspace again
                std::cout << "\b \b";
            }
            continue;
        }
        passwd.push_back(c);
        _putch('*');  // Print mask character
    }
    // Add a newline to move the cursor to the next line after input
    std::cout << '\n';

    // For testing only: Never print the actual password in production!
    std::cout << "You entered: " << passwd << std::endl;
    return 0;
}

Key Fixes & Improvements: #

• Enter Key Detection: Swapped the check from '\n' to '\r'—this matches what _getch() actually returns when you press Enter on Windows.
• Variable Declaration: Added std::string passwd; and included the <string> header (your original code was missing this, which would cause a compile error).
• Backspace Support: Added optional logic to handle backspace presses, so users can delete characters they typed by pressing Backspace—this makes the input feel much more natural.
• Clean Line Break: Added std::cout << '\n'; after the loop to move the cursor to a new line, so subsequent output doesn't sit right next to the password masks.

Note: _getch() is a Windows-specific function from <conio.h>. If you need cross-platform password masking, you'd need to use alternative methods (like reading from stdin with terminal settings modified), but this works perfectly for Windows environments.

内容的提问来源于stack exchange，提问作者coxijr