密码屏蔽控制台应用程序

Question

我想下面的代码...

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); 

但是这样一来，同时输入密码的回退功能不起作用。 有什么建议吗？

Answer 1

Console.Write("\b \b");会从屏幕中删除星号，但你没有你的else块移除先前输入的字符中的任何代码来自您的pass字符串变量。

下面是应该做的，你需要什么相关的代码部分（if..else部分）：

// Backspace Should Not Work 
if (key.Key != ConsoleKey.Backspace && key.Key != ConsoleKey.Enter) 
{ 
    pass += key.KeyChar; 
    Console.Write("*"); 
} 
else 
{ 
    if (key.Key == ConsoleKey.Backspace && pass.Length > 0) 
    { 
     pass = pass.Substring(0, (pass.Length - 1)); 
     Console.Write("\b \b"); 
    } 
} 

Answer 2

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 
     { 
      pwd.AppendChar(i.KeyChar); 
      Console.Write("*"); 
     } 
    } 
    return pwd; 
} 

Answer 3

你可以添加你的钥匙到积累链表。

收到退格键时，从列表中删除最后一个键。

当您收到回车键时，将您的列表折叠成一个字符串并完成其余的工作。

Answer 4

如果我正确地理解了这一点，你试图让退格键同时删除屏幕上的可见*字符和传递变量中的缓存字符？

如果是这样，那么就你else块改成这样：

  else 
      { 
       Console.Write("\b"); 
       pass = pass.Remove(pass.Length -1); 
      } 

Answer 5

完整的解决方案，香草C＃.NET 3.5+

剪切粘贴& :)

using System; 
    using System.Collections.Generic; 
    using System.Linq; 
    using System.Text; 

    namespace ConsoleReadPasswords 
    { 
     class Program 
     { 
      static void Main(string[] args) 
      { 
       Console.Write("Password:"); 

       string password = Orb.App.Console.ReadPassword(); 

       Console.WriteLine("Sorry - I just can't keep a secret!"); 
       Console.WriteLine("Your password was:\n<Password>{0}</Password>", password); 

       Console.ReadLine(); 
      } 
     } 
    } 

    namespace Orb.App 
    { 
     /// <summary> 
     /// Adds some nice help to the console. Static extension methods don't exist (probably for a good reason) so the next best thing is congruent naming. 
     /// </summary> 
     static public class Console 
     { 
      /// <summary> 
      /// Like System.Console.ReadLine(), only with a mask. 
      /// </summary> 
      /// <param name="mask">a <c>char</c> representing your choice of console mask</param> 
      /// <returns>the string the user typed in </returns> 
      public static string ReadPassword(char mask) 
      { 
       const int ENTER = 13, BACKSP = 8, CTRLBACKSP = 127; 
       int[] FILTERED = { 0, 27, 9, 10 /*, 32 space, if you care */ }; // const 

       var pass = new Stack<char>(); 
       char chr = (char)0; 

       while ((chr = System.Console.ReadKey(true).KeyChar) != ENTER) 
       { 
        if (chr == BACKSP) 
        { 
         if (pass.Count > 0) 
         { 
          System.Console.Write("\b \b"); 
          pass.Pop(); 
         } 
        } 
        else if (chr == CTRLBACKSP) 
        { 
         while (pass.Count > 0) 
         { 
          System.Console.Write("\b \b"); 
          pass.Pop(); 
         } 
        } 
        else if (FILTERED.Count(x => chr == x) > 0) { } 
        else 
        { 
         pass.Push((char)chr); 
         System.Console.Write(mask); 
        } 
       } 

       System.Console.WriteLine(); 

       return new string(pass.Reverse().ToArray()); 
      } 

      /// <summary> 
      /// Like System.Console.ReadLine(), only with a mask. 
      /// </summary> 
      /// <returns>the string the user typed in </returns> 
      public static string ReadPassword() 
      { 
       return Orb.App.Console.ReadPassword('*'); 
      } 
     } 
    } 

Answer 6

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); 

Answer 7

矿忽略控制字符和处理换行：

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(); 
} 

Answer 8

我已经花了太多时间试图只有输入密码才能发现，我有我的CAPS LOCK后更新罗尼的版本！

有了这个版本，_CapsLockMessage的信息将在输入区域的末尾“浮动”，并以红色显示。

该版本需要更多的代码，并且需要轮询循环。在我的电脑CPU使用率约为3％到4％，但总是可以添加一个小的Sleep（）值，以便在需要时减少CPU使用率。

private const string _CapsLockMessage = " CAPS LOCK"; 

    /// <summary> 
    /// Like System.Console.ReadLine(), only with a mask. 
    /// </summary> 
    /// <param name="mask">a <c>char</c> representing your choice of console mask</param> 
    /// <returns>the string the user typed in</returns> 
    public static string ReadLineMasked(char mask = '*') 
    { 
     // Taken from http://stackoverflow.com/a/19770778/486660 
     var consoleLine = new StringBuilder(); 
     ConsoleKeyInfo keyInfo; 
     bool isDone; 
     bool isAlreadyLocked; 
     bool isCapsLockOn; 
     int cursorLeft; 
     int cursorTop; 
     ConsoleColor originalForegroundColor; 

     isDone = false; 
     isAlreadyLocked = Console.CapsLock; 

     while (isDone == false) 
     { 
      isCapsLockOn = Console.CapsLock; 
      if (isCapsLockOn != isAlreadyLocked) 
      { 
       if (isCapsLockOn) 
       { 
        cursorLeft = Console.CursorLeft; 
        cursorTop = Console.CursorTop; 
        originalForegroundColor = Console.ForegroundColor; 
        Console.ForegroundColor = ConsoleColor.Red; 
        Console.Write("{0}", _CapsLockMessage); 
        Console.SetCursorPosition(cursorLeft, cursorTop); 
        Console.ForegroundColor = originalForegroundColor; 
       } 
       else 
       { 
        cursorLeft = Console.CursorLeft; 
        cursorTop = Console.CursorTop; 
        Console.Write("{0}", string.Empty.PadRight(_CapsLockMessage.Length)); 
        Console.SetCursorPosition(cursorLeft, cursorTop); 
       } 
       isAlreadyLocked = isCapsLockOn; 
      } 

      if (Console.KeyAvailable) 
      { 
       keyInfo = Console.ReadKey(intercept: true); 

       if (keyInfo.Key == ConsoleKey.Enter) 
       { 
        isDone = true; 
        continue; 
       } 

       if (!char.IsControl(keyInfo.KeyChar)) 
       { 
        consoleLine.Append(keyInfo.KeyChar); 
        Console.Write(mask); 
       } 
       else if (keyInfo.Key == ConsoleKey.Backspace && consoleLine.Length > 0) 
       { 
        consoleLine.Remove(consoleLine.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"); 
        } 
       } 

       if (isCapsLockOn) 
       { 
        cursorLeft = Console.CursorLeft; 
        cursorTop = Console.CursorTop; 
        originalForegroundColor = Console.ForegroundColor; 
        Console.ForegroundColor = ConsoleColor.Red; 
        Console.Write("{0}", _CapsLockMessage); 
        Console.CursorLeft = cursorLeft; 
        Console.CursorTop = cursorTop; 
        Console.ForegroundColor = originalForegroundColor; 
       } 
      } 
     } 

     Console.WriteLine(); 

     return consoleLine.ToString(); 
    } 

Answer 9

 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); 

Answer 10

我发现了一个bug在shermy的香草C＃3.5 .NET解决方案，否则工作的魅力。我也加入了DamianLeszczyński - Vash的SecureString理念，但如果您愿意的话，您可以使用普通的字符串。

错误：如果您在密码提示期间按退格键，且密码的当前长度为0，则会在密码掩码中错误地插入星号。要修复此错误，请修改以下方法。

public static string ReadPassword(char mask) 
    { 
     const int ENTER = 13, BACKSP = 8, CTRLBACKSP = 127; 
     int[] FILTERED = { 0, 27, 9, 10 /*, 32 space, if you care */ }; // const 


     SecureString securePass = new SecureString(); 

     char chr = (char)0; 

     while ((chr = System.Console.ReadKey(true).KeyChar) != ENTER) 
     { 
      if (((chr == BACKSP) || (chr == CTRLBACKSP)) 
       && (securePass.Length > 0)) 
      { 
       System.Console.Write("\b \b"); 
       securePass.RemoveAt(securePass.Length - 1); 

      } 
      // Don't append * when length is 0 and backspace is selected 
      else if (((chr == BACKSP) || (chr == CTRLBACKSP)) && (securePass.Length == 0)) 
      { 
      } 

      // Don't append when a filtered char is detected 
      else if (FILTERED.Count(x => chr == x) > 0) 
      { 
      } 

      // Append and write * mask 
      else 
      { 
       securePass.AppendChar(chr); 
       System.Console.Write(mask); 
      } 
     } 

     System.Console.WriteLine(); 
     IntPtr ptr = new IntPtr(); 
     ptr = Marshal.SecureStringToBSTR(securePass); 
     string plainPass = Marshal.PtrToStringBSTR(ptr); 
     Marshal.ZeroFreeBSTR(ptr); 
     return plainPass; 
    } 

Answer 11

阅读控制台输入很难，您需要处理特殊的按键，如Ctrl，Alt，光标键和Backspace/Delete。在某些键盘布局上，如Swedish甚至需要使用Ctrl键输入直接存在于美式键盘上的键。我相信试图使用“低级”Console.ReadKey(true)来处理这个问题非常困难，所以最简单和最可靠的方法就是在使用一点WINAPI输入密码期间禁用“控制台输入回显”。

以下示例基于回答Read a password from std::cin问题。

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; 
    } 

Answer 12

考虑最多的回答，以及来自它的意见建议，并修改它使用SecureString的，而不是字符串，测试的所有控制键，而不是错误或者写一个额外的“*”屏幕当密码长度为0，我的解决方案是：

public static SecureString getPasswordFromConsole(String displayMessage) { 
    SecureString pass = new SecureString(); 
    Console.Write(displayMessage); 
    ConsoleKeyInfo key; 

    do { 
     key = Console.ReadKey(true); 

     // Backspace Should Not Work 
     if (!char.IsControl(key.KeyChar)) { 
      pass.AppendChar(key.KeyChar); 
      Console.Write("*"); 
     } else { 
      if (key.Key == ConsoleKey.Backspace && pass.Length > 0) { 
       pass.RemoveAt(pass.Length - 1); 
       Console.Write("\b \b"); 
      } 
     } 
    } 
    // Stops Receving Keys Once Enter is Pressed 
    while (key.Key != ConsoleKey.Enter); 
    return pass; 
} 

Answer 13

这掩盖了红色正方形的密码，然后恢复到原来的颜色，一旦密码已输入。

它不会阻止用户使用复制/粘贴来获取密码，但如果它更多的是阻止某个人看着你的肩膀，这是一个很好的快速解决方案。

Console.Write("Password "); 
ConsoleColor origBG = Console.BackgroundColor; // Store original values 
ConsoleColor origFG = Console.ForegroundColor; 

Console.BackgroundColor = ConsoleColor.Red; // Set the block colour (could be anything) 
Console.ForegroundColor = ConsoleColor.Red; 

string Password = Console.ReadLine(); // read the password 

Console.BackgroundColor= origBG; // revert back to original 
Console.ForegroundColor= origFG;