Listen on ESC while reading Console line

Question

I want to read an users input into a string while still reacting on ESC press at any time, but without defining a system wide hotkey.

So when the user types e. g. "Test Name" but instead of confirming with ENTER presses ESC he should be led back into main menu.

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

Thats the simplest way I could think of, but since ESC is not seen by Console.ReadLine() it is not working.

Found a rather complex way to react on ESC when pressed before starting to enter text here, but I want it to work at any time.

Answer 1

You will probably have to forego the use of ReadLine and roll your own using 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;
}

This code is not complete and may require work to make it robust, but it should give you some ideas.