c# console snake gets stuck on long key press

Question

I just started learning programming couple months ago and decided to do a console snake game. Everything works great expect for one thing.

If my snake is going upwards and I press down arrow and keep it pressed, my snake just stops and stays stopped even awhile after I stop pressing the button.

Same thing happens if my snake is going right and I press right arrow too long, I lose control for some time(but snake does not stop). It happens for every way(left,right,up,down).

I tried to compare the cki to another ConsoleKeyInfo with slight delay between them, but it doesn't matter. If I keep the key pressed, my program just stays that spot and updates for a key. (atleast I think thats the problem)

Is this a "feature" of the Console.ReadKey or is there some way arount this?

Keep in mind, that I just started so I don't know about the advanced stuff, yet.

Everything works flawless as long as I don't keep the key pressed more than 1 sec.

   public void LiikutaMato() //movesnake
    {

        if (Console.KeyAvailable)
        {
                ConsoleKeyInfo cki;
                cki = Console.ReadKey(true); // <-- I believe this is where it gets stuck 

    }

Answer 1

Play with this...it uses a tight loop to consume the keypresses until the set delay has expired. You also don't have to hold down the key to keep the snake moving. It was very responsive on my system:

class Program
{

    public enum Direction
    {
        Up, 
        Down, 
        Right, 
        Left
    }

    static void Main(string[] args)
    {
        const int delay = 75;
        string snake = "O";
        char border = 'X';

        int x, y;
        int length;
        bool crashed = false;
        Direction curDirection = Direction.Up;
        Dictionary<string, bool> eaten = new Dictionary<string, bool>();
        Console.CursorVisible = false;

        ConsoleKeyInfo cki;
        bool quit = false;
        while (!quit)
        {
            Console.Clear();
            Console.Title = "Use 'a', 's', 'd' and 'w' to steer.  Hit 'q' to quit.";

            // draw border around the console:
            string row = new String(border, Console.WindowWidth);
            Console.SetCursorPosition(0, 0);
            Console.Write(row);
            Console.SetCursorPosition(0, Console.WindowHeight - 2);
            Console.Write(row);
            for (int borderY = 0; borderY < Console.WindowHeight - 2; borderY++)
            {
                Console.SetCursorPosition(0, borderY);
                Console.Write(border.ToString());
                Console.SetCursorPosition(Console.WindowWidth - 1, borderY);
                Console.Write(border.ToString());
            }

            // reset all game variables:
            length = 1;
            crashed = false;
            curDirection = Direction.Up;
            eaten.Clear();
            x = Console.WindowWidth / 2;
            y = Console.WindowHeight / 2;
            eaten.Add(x.ToString("00") + y.ToString("00"), true);

            // draw new snake:
            Console.SetCursorPosition(x, y);
            Console.Write(snake);

            // wait for initial keypress:
            while (!Console.KeyAvailable)
            {
                System.Threading.Thread.Sleep(10);
            }

            // see if intitial direction should be changed:
            cki = Console.ReadKey(true);
            switch (cki.KeyChar)
            {
                case 'w':
                    curDirection = Direction.Up;
                    break;

                case 's':
                    curDirection = Direction.Down;
                    break;

                case 'a':
                    curDirection = Direction.Left;
                    break;

                case 'd':
                    curDirection = Direction.Right;
                    break;

                case 'q':
                    quit = true;
                    break;
            }

            // main game loop:
            DateTime nextCheck = DateTime.Now.AddMilliseconds(delay);
            while (!quit && !crashed)
            {
                Console.Title = "Length: " + length.ToString();

                // consume keystrokes and change current direction until the delay has expired:
                // *The snake won't actually move until after the delay!
                while (nextCheck > DateTime.Now)
                {
                    if (Console.KeyAvailable)
                    {
                        cki = Console.ReadKey(true);
                        switch (cki.KeyChar)
                        {
                            case 'w':
                                curDirection = Direction.Up;
                                break;

                            case 's':
                                curDirection = Direction.Down;
                                break;

                            case 'a':
                                curDirection = Direction.Left;
                                break;

                            case 'd':
                                curDirection = Direction.Right;
                                break;

                            case 'q':
                                quit = true;
                                break;
                        }
                    }
                }

                // if the user didn't quit, attempt to move without hitting the border:
                if (!quit)
                {
                    string key = "";
                    switch (curDirection)
                    {
                        case Direction.Up:
                            if (y > 1)
                            {
                                y--;
                            }
                            else
                            {
                                crashed = true;
                            }
                            break;

                        case Direction.Down:
                            if (y < Console.WindowHeight - 3)
                            {
                                y++;
                            }
                            else
                            {
                                crashed = true;
                            }
                            break;

                        case Direction.Left:
                            if (x > 1)
                            {
                                x--;
                            }
                            else
                            {
                                crashed = true;
                            }

                            break;

                        case Direction.Right:
                            if (x < Console.WindowWidth - 2)
                            {
                                x++;
                            }
                            else
                            {
                                crashed = true;
                            }
                            break;
                    }

                    // if the user didn't hit the border, see if they hit the snake
                    if (!crashed)
                    {
                        key = x.ToString("00") + y.ToString("00");
                        if (!eaten.ContainsKey(key))
                        {
                            length++;
                            eaten.Add(key, true);
                            Console.SetCursorPosition(x, y);
                            Console.Write(snake);
                        }
                        else
                        {
                            crashed = true;
                        }
                    }

                    // set the next delay:
                    nextCheck = DateTime.Now.AddMilliseconds(delay);
                }
            } // end main game loop

            if (crashed)
            {
                Console.Title = "*** Crashed! *** Length: " + length.ToString() + "     Hit 'q' to quit, or 'r' to retry!";

                // wait for quit or retry:
                bool retry = false;
                while (!quit && !retry)
                {
                    if (Console.KeyAvailable)
                    {
                        cki = Console.ReadKey(true);
                        switch (cki.KeyChar)
                        {
                            case 'q':
                                quit = true;
                                break;

                            case 'r':
                                retry = true;
                                break;
                        }
                    }
                }
            } 

        } // end main program loop

    } // end Main()

}