密码屏蔽控制台应用程序

我尝试了下面的代码…

string pass = "";
Console.Write("Enter your password: ");
ConsoleKeyInfo key;

do
{
    key = Console.ReadKey(true);

    // Backspace Should Not Work
    if (key.Key != ConsoleKey.Backspace)
    {
        pass += key.KeyChar;
        Console.Write("*");
    }
    else
    {
        Console.Write("\b");
    }
}
// Stops Receving Keys Once Enter is Pressed
while (key.Key != ConsoleKey.Enter);

Console.WriteLine();
Console.WriteLine("The Password You entered is : " + pass);

但是这样的话，退格键在输入密码时就不起作用了。任何建议吗?

当前回答

读取控制台输入是困难的，你需要处理特殊的键，如Ctrl, Alt，还有光标键和退格/删除。在一些键盘布局中，像瑞典式Ctrl甚至需要输入直接存在于美国键盘上的键。我相信尝试使用“低级”console . readkey (true)来处理这个问题是非常困难的，所以最简单和最健壮的方法是在输入密码时禁用“控制台输入回声”，使用一点WINAPI。

下面的示例是基于从std::cin问题读取密码的答案。

    private enum StdHandle
    {
        Input = -10,
        Output = -11,
        Error = -12,
    }

    private enum ConsoleMode
    {
        ENABLE_ECHO_INPUT = 4
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern IntPtr GetStdHandle(StdHandle nStdHandle);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetConsoleMode(IntPtr hConsoleHandle, out int lpMode);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool SetConsoleMode(IntPtr hConsoleHandle, int dwMode);

    public static string ReadPassword()
    {
        IntPtr stdInputHandle = GetStdHandle(StdHandle.Input);
        if (stdInputHandle == IntPtr.Zero)
        {
            throw new InvalidOperationException("No console input");
        }

        int previousConsoleMode;
        if (!GetConsoleMode(stdInputHandle , out previousConsoleMode))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not get console mode.");
        }

        // disable console input echo
        if (!SetConsoleMode(stdInputHandle , previousConsoleMode & ~(int)ConsoleMode.ENABLE_ECHO_INPUT))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not disable console input echo.");
        }

        // just read the password using standard Console.ReadLine()
        string password = Console.ReadLine();

        // reset console mode to previous
        if (!SetConsoleMode(stdInputHandle , previousConsoleMode))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not reset console mode.");
        }

        return password;
    }

2016-03-16 07:54:08

其他回答

下面的示例是基于从std::cin问题读取密码的答案。

    private enum StdHandle
    {
        Input = -10,
        Output = -11,
        Error = -12,
    }

    private enum ConsoleMode
    {
        ENABLE_ECHO_INPUT = 4
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern IntPtr GetStdHandle(StdHandle nStdHandle);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetConsoleMode(IntPtr hConsoleHandle, out int lpMode);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool SetConsoleMode(IntPtr hConsoleHandle, int dwMode);

    public static string ReadPassword()
    {
        IntPtr stdInputHandle = GetStdHandle(StdHandle.Input);
        if (stdInputHandle == IntPtr.Zero)
        {
            throw new InvalidOperationException("No console input");
        }

        int previousConsoleMode;
        if (!GetConsoleMode(stdInputHandle , out previousConsoleMode))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not get console mode.");
        }

        // disable console input echo
        if (!SetConsoleMode(stdInputHandle , previousConsoleMode & ~(int)ConsoleMode.ENABLE_ECHO_INPUT))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not disable console input echo.");
        }

        // just read the password using standard Console.ReadLine()
        string password = Console.ReadLine();

        // reset console mode to previous
        if (!SetConsoleMode(stdInputHandle , previousConsoleMode))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not reset console mode.");
        }

        return password;
    }

2016-03-16 07:54:08

我的忽略控制字符和处理行换行:

public static string ReadLineMasked(char mask = '*')
{
    var sb = new StringBuilder();
    ConsoleKeyInfo keyInfo;
    while ((keyInfo = Console.ReadKey(true)).Key != ConsoleKey.Enter)
    {
        if (!char.IsControl(keyInfo.KeyChar))
        {
            sb.Append(keyInfo.KeyChar);
            Console.Write(mask);
        }
        else if (keyInfo.Key == ConsoleKey.Backspace && sb.Length > 0)
        {
            sb.Remove(sb.Length - 1, 1);

            if (Console.CursorLeft == 0)
            {
                Console.SetCursorPosition(Console.BufferWidth - 1, Console.CursorTop - 1);
                Console.Write(' ');
                Console.SetCursorPosition(Console.BufferWidth - 1, Console.CursorTop - 1);
            }
            else Console.Write("\b \b");
        }
    }
    Console.WriteLine();
    return sb.ToString();
}

2013-11-04 15:12:15

为此，您应该使用System.Security.SecureString

public SecureString GetPassword()
{
    var pwd = new SecureString();
    while (true)
    {
        ConsoleKeyInfo i = Console.ReadKey(true);
        if (i.Key == ConsoleKey.Enter)
        {
            break;
        }
        else if (i.Key == ConsoleKey.Backspace)
        {
            if (pwd.Length > 0)
            {
                pwd.RemoveAt(pwd.Length - 1);
                Console.Write("\b \b");
            }
        }
        else if (i.KeyChar != '\u0000' ) // KeyChar == '\u0000' if the key pressed does not correspond to a printable character, e.g. F1, Pause-Break, etc
        {
            pwd.AppendChar(i.KeyChar);
            Console.Write("*");
        }
    }
    return pwd;
}

2010-08-04 10:05:08

 string pass = "";
 Console.WriteLine("Enter your password: ");
 ConsoleKeyInfo key;

 do {
  key = Console.ReadKey(true);

  if (key.Key != ConsoleKey.Backspace) {
   pass += key.KeyChar;
   Console.Write("*");
  } else {
   Console.Write("\b \b");
   char[] pas = pass.ToCharArray();
   string temp = "";
   for (int i = 0; i < pass.Length - 1; i++) {
    temp += pas[i];
   }
   pass = temp;
  }
 }
 // Stops Receving Keys Once Enter is Pressed
 while (key.Key != ConsoleKey.Enter);

 Console.WriteLine();
 Console.WriteLine("The Password You entered is : " + pass);

2015-08-01 17:30:37

我对退格做了一些修改

        string pass = "";
        Console.Write("Enter your password: ");
        ConsoleKeyInfo key;

        do
        {
            key = Console.ReadKey(true);

            // Backspace Should Not Work
            if (key.Key != ConsoleKey.Backspace)
            {
                pass += key.KeyChar;
                Console.Write("*");
            }
            else
            {
                pass = pass.Remove(pass.Length - 1);
                Console.Write("\b \b");
            }
        }
        // Stops Receving Keys Once Enter is Pressed
        while (key.Key != ConsoleKey.Enter);

        Console.WriteLine();
        Console.WriteLine("The Password You entered is : " + pass);

2013-05-03 09:41:46

密码屏蔽控制台应用程序

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