2 responses to “C# Tutorial – How to make a Classic Snakes Game with Windows form and Visual Studio [Updated]”

1. Volkan Coskun says:

   September 6, 2021 at 11:04 am

   is there any reason you have flags to indicate left,right,up & down?
   Also, is the KeyIsUp function needed ?

2. Volkan Coskun says:

   September 6, 2021 at 12:46 pm

   I refactored your code to :

   using System;
   using System.Collections.Generic;
   using System.ComponentModel;
   using System.Data;
   using System.Drawing;
   using System.Linq;
   using System.Text;
   using System.Threading.Tasks;
   using System.Windows.Forms;
   static class Constants
   {
   public const int headPos = 0;
   public const int gameTimerInterval = 500;
   }

   namespace snake
   {
   public partial class Form1 : Form
   {
   private List Snake = new List();
   private Circle food = new Circle();
   int maxWidth;
   int maxHeight;
   Random rand = new Random();

   public Form1()
   {
   InitializeComponent();
   new setting();
   }
   private void KeyIsDown(object sender, KeyEventArgs e)
   {
   if (e.KeyCode == Keys.Left && setting.direction != “RIGHT”)
   {
   setting.direction = “LEFT”;
   }
   if (e.KeyCode == Keys.Right && setting.direction != “LEFT”)
   {
   setting.direction = “RIGHT”;
   }
   if (e.KeyCode == Keys.Up && setting.direction != “DOWN”)
   {
   setting.direction = “UP”;
   }
   if (e.KeyCode == Keys.Down && setting.direction != “UP”)
   {
   setting.direction = “DOWN”;
   }
   }
   private void StartGame(object sender, EventArgs e)
   {
   RestartGame();
   }
   private void GameTimerEvent(object sender, EventArgs e)
   {
   checkFood();

   for (int bodyIndex = Snake.Count – 1; bodyIndex >= 0; bodyIndex–)
   {
   if (bodyIndex == Constants.headPos)
   {
   updateSnakePos();
   }
   else
   {
   Snake[bodyIndex].X = Snake[bodyIndex – 1].X;
   Snake[bodyIndex].Y = Snake[bodyIndex – 1].Y;
   }
   }
   checkSnakeCollision();
   picCanvas.Invalidate();
   }
   private void updateSnakePos()
   {
   switch (setting.direction)
   {
   case “LEFT”:
   Snake[Constants.headPos].X–;

   if (Snake[Constants.headPos].X maxWidth)
   {
   gameOver();
   }
   break;
   case “DOWN”:
   Snake[Constants.headPos].Y++;

   if (Snake[Constants.headPos].Y > maxHeight)
   {
   gameOver();
   }
   break;
   case “UP”:
   Snake[Constants.headPos].Y–;

   if (Snake[Constants.headPos].Y < 0)
   {
   gameOver();
   }
   break;
   default:
   break;
   }
   }
   private void drawSnake(object sender, PaintEventArgs e)
   {
   Graphics canvas = e.Graphics;

   for (int i = 0; i < Snake.Count; i++)
   {
   canvas.FillEllipse((i == Constants.headPos) ? Brushes.Black : Brushes.DarkGreen, new Rectangle(Snake[i].X * setting.Width, Snake[i].Y * setting.Height, setting.Width, setting.Height));
   }
   canvas.FillEllipse(Brushes.DarkRed, new Rectangle(food.X * setting.Width, food.Y * setting.Height, setting.Width, setting.Height));
   }

   private void RestartGame()
   {
   maxWidth = picCanvas.Width / setting.Width – 1;
   maxHeight = picCanvas.Height / setting.Height – 1;

   Snake.Clear();

   startButton.Enabled = false;

   Circle head = new Circle { X = rand.Next(2, maxWidth), Y = rand.Next(2, maxHeight)};
   Snake.Add(head); // adding the head part of the snake to the list

   for (int i = 0; i < 3; i++)
   {
   Circle body = new Circle();
   Snake.Add(body);
   }

   food = new Circle { X = rand.Next(2, maxWidth), Y = rand.Next(2, maxHeight) };

   gameTimer.Start();
   }

   private void checkSnakeCollision()
   {
   for (int j = 1; j < Snake.Count; j++)
   {
   if (Snake[Constants.headPos].X == Snake[j].X && Snake[Constants.headPos].Y == Snake[j].Y)
   {
   gameOver();
   }
   }
   }

   private void gameOver()
   {
   gameTimer.Interval = Constants.gameTimerInterval;
   gameTimer.Stop();
   startButton.Enabled = true;
   }
   private void checkFood()
   {
   if (Snake[Constants.headPos].X == food.X && Snake[Constants.headPos].Y == food.Y)
   {
   Circle body = new Circle
   {
   X = Snake[Snake.Count – 1].X,
   Y = Snake[Snake.Count – 1].Y
   };

   if(gameTimer.Interval / 2 == 0)
   {
   gameTimer.Interval = 5;
   }
   else
   {
   gameTimer.Interval = gameTimer.Interval / 2;
   }
   Snake.Add(body);

   food = new Circle { X = rand.Next(2, maxWidth), Y = rand.Next(2, maxHeight) };
   }
   }
   }
   }