Console ReadKey async or callback?

Question

I am trying to do a press Q to quit thing in the console window. I dont like my current implementation. Is there a way i can async or use a callback to get keys from the con

Answer 1

Here is an implementation that I created using KeyAvailable. This keeps a prompt at the bottom of the console window while everything "printed" to the console starts from the top.

public class Program
{
    private static int consoleLine;
    private static int consolePromptLine;
    private static bool exit;
    static string clearLine = new string(' ', Console.BufferWidth - 1);

    public static void Main(string[] args)
    {
        StringBuilder commandCapture = new StringBuilder(10);
        string promptArea = "Command> ";

        consolePromptLine = Console.WindowTop + Console.WindowHeight - 1;

        ClearLine(consolePromptLine);
        Console.Write(promptArea);

        while (!exit)
        {
            // Do other stuff

            // Process input
            if (Console.KeyAvailable)
            {
                var character = Console.ReadKey(true);

                if (character.Key == ConsoleKey.Enter)
                {
                    if (commandCapture.Length != 0)
                    {
                        ProcessCommand(commandCapture.ToString());
                        commandCapture.Clear();
                        ClearLine(consolePromptLine);
                        Console.Write(promptArea);
                    }
                }
                else
                {
                    if (character.Key == ConsoleKey.Backspace)
                    {
                        if (commandCapture.Length != 0)
                        {
                            commandCapture.Remove(commandCapture.Length - 1, 1);
                            ClearLine(consolePromptLine);
                            Console.Write(promptArea);
                            Console.Write(commandCapture.ToString());
                        }
                    }
                    else
                    {
                        commandCapture.Append(character.KeyChar);
                        Console.SetCursorPosition(0, consolePromptLine);
                        Console.Write(promptArea);
                        Console.Write(commandCapture.ToString());
                    }
                }
            }
        }

    }

    private static void ProcessCommand(string command)
    {
        if (command == "start")
        {
            Task testTask = new Task(() => { System.Threading.Thread.Sleep(4000); return "Test Complete"; });

            testTask.ContinueWith((t) => { Print(t.Result); }, TaskContinuationOptions.ExecuteSynchronously);
            testTask.Start();
        }
        else if (command == "quit")
        {
            exit = true;
        }

        Print(command);
        consolePromptLine = Console.WindowTop + Console.WindowHeight - 1;
    }

    public static void Print(string text)
    {
        ClearLine(consoleLine);
        Console.WriteLine(text);
        consoleLine = Console.CursorTop;
    }

    public static void ClearLine(int line)
    {
        Console.SetCursorPosition(0, line);
        Console.Write(clearLine);
        Console.SetCursorPosition(0, line);
    }
}