在阅读控制台线时听ESC

Question

我想将用户输入读入一个字符串,同时仍然可以随时在ESC按下,但是没有定义系统范围的热键.

因此,当用户键入例如"测试名称"但不是用ENTER确认按ESC时,他应该被带回主菜单.

Console.Write("Enter name: ")
if (Console.ReadLine().Contains(ConsoleKey.Escape.ToString()))
{
    goto MainMenu;
}
return Console.ReadLine();

这是我能想到的最简单的方式,但由于ESC没有看到Console.ReadLine()它不起作用.

发现了一个相当复杂的方式时按下ESC上反应之前开始输入文字在这里,但我希望它在工作的任何时间.

Answer 1

您可能不得不放弃使用ReadLine和滚动自己使用ReadKey:

static void Main(string[] args)
{
    Console.Clear();
    Console.Write("Enter your name and press ENTER.  (ESC to cancel): ");
    string name = readLineWithCancel();

    Console.WriteLine("\r\n{0}", name == null ? "Cancelled" : name);

    Console.ReadLine();
}

//Returns null if ESC key pressed during input.
private static string readLineWithCancel()
{
    string result = null;

    StringBuilder buffer = new StringBuilder();

    //The key is read passing true for the intercept argument to prevent
    //any characters from displaying when the Escape key is pressed.
    ConsoleKeyInfo info = Console.ReadKey(true);
    while (info.Key != ConsoleKey.Enter && info.Key != ConsoleKey.Escape)
    {
        Console.Write(info.KeyChar);
        buffer.Append(info.KeyChar);
        info = Console.ReadKey(true);
    } 

    if (info.Key == ConsoleKey.Enter)
    {
        result = buffer.ToString();
    }

    return result;
}

此代码不完整,可能需要工作以使其健壮,但它应该给你一些想法.

Answer 2

克里斯·达纳韦的的一点改进版一个：

    public static bool CancelableReadLine(out string value)
    {
        value = string.Empty;
        var buffer = new StringBuilder();
        var key = Console.ReadKey(true);
        while (key.Key != ConsoleKey.Enter && key.Key != ConsoleKey.Escape)
        {
            if (key.Key == ConsoleKey.Backspace && Console.CursorLeft > 0)
            {
                var cli = --Console.CursorLeft;
                buffer.Remove(cli, 1);
                Console.CursorLeft = 0;
                Console.Write(new String(Enumerable.Range(0, buffer.Length + 1).Select(o => ' ').ToArray()));
                Console.CursorLeft = 0;
                Console.Write(buffer.ToString());
                Console.CursorLeft = cli;
                key = Console.ReadKey(true);
            }
            else if (Char.IsLetterOrDigit(key.KeyChar) || Char.IsWhiteSpace(key.KeyChar))
            {
                var cli = Console.CursorLeft;
                buffer.Insert(cli, key.KeyChar);
                Console.CursorLeft = 0;
                Console.Write(buffer.ToString());
                Console.CursorLeft = cli + 1;
                key = Console.ReadKey(true);
            }
            else if (key.Key == ConsoleKey.LeftArrow && Console.CursorLeft > 0)
            {
                Console.CursorLeft--;
                key = Console.ReadKey(true);
            }
            else if (key.Key == ConsoleKey.RightArrow && Console.CursorLeft < buffer.Length)
            {
                Console.CursorLeft++;
                key = Console.ReadKey(true);
            }
            else
            {
                key = Console.ReadKey(true);
            }
        }

        if (key.Key == ConsoleKey.Enter)
        {
            Console.WriteLine();
            value = buffer.ToString();
            return true;
        }
        return false;
    }
}

我没有对其进行太多测试，但至少对我有用。