C# - Console How to get input every frame

Question

So, I was bored and decided to write an ASCII game in C# for the fun of it, and I have drawing, clearing, updating, etc.. Although, I'm stuck at one part, input. I want to get input every frame, without the player pressing enter, So far the player has to press enter, but it doesn't do anything.

Here is my code:

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

namespace ASCII
{
    public static class Game
    {
        static string map = File.ReadAllText("Map.txt");
        public static void Draw()
        {
            Console.CursorVisible = false;
            Console.WriteLine(map);
        }

        public static void Update()
        {
            Clear();
            Input();
        }

        public static void Input()
        {
            string input = Console.ReadLine();

            switch (input)
            {
                case "a":
                    //Do something
                    break;
            }
        }

        public static void Clear()
        {
            Console.Clear();
            Draw();
        }
    }
}

As you can see in the Input() void, it gets input every frame, but I only want to get it once, the do a move method or something that I will implement later.

BTW Map.txt displays this:

###################

# #

# @ # #

######## #

# #

# #

# #

# #

# #

# #

# #

###################

Answer 1

Console.ReadLine will wait for the enter-key to continue making the application kind of modal. What you want instead is handle keyboard-events on the concole. So you could use ReadKey instead:

var input = Console.ReadKey(true);

switch (input.Key)
{
    case ConsoleKey.A:
        //Do something
        break;
}

To hold on moving you may implement this in a loop. The key here is to remember your current action until the next key-event passes

int action = 0;
while(!exit) 
{
    // handle the action
    myPlayer.X += action; // move player left or right depending on the previously pressed key (A or D)

    if(!Console.KeyAvailable) continue;
    var input = Console.ReadKey(true);

    switch (input.Key)
    {
        case ConsoleKey.A:
            action = -1
            break;
        case ConsoleKey.D:
            action = 1
            break;
    }    
}

Answer 2

I'm not sure I understood the question right, but if I did, you can use Console.KeyAvailable and Console.ReadKey to check if a key is available before reading it.

So something like:

public static void Input()
{
   if(!Console.KeyAvailable) return;
   ConsoleKeyInfo key = Console.ReadKey(true);

   switch (key.Key)
   {
      case ConsoleKey.A:
         //Do something
          break;
   }
}