SnakeWinForm2b

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;

namespace SnakeWinForm2b
{
    public partial class Form1 : Form
    {
        private int positionX = 0;
        private int positionY = 0;
        public Form1()
        {
            InitializeComponent();
            timer1.Interval = 100;
            timer1.Tick += UpdateScreen;
            timer1.Start();
        }

        private void UpdateScreen(object sender, EventArgs e)
        {
            pbGame.Invalidate();
        }
        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void pbGame_Paint(object sender, PaintEventArgs e)
        {
            Graphics canvas = e.Graphics;
            canvas.FillEllipse(Brushes.Red,
                new Rectangle(positionX, positionY, 20, 20));
        }

        private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode) {
                case Keys.Right :
                    positionX++;
                    break;
                case Keys.Left:
                    positionX--;
                    break;
                case Keys.Up:
                    positionY--;
                    break;
                case Keys.Down:
                    positionY++;
                    break;
                case Keys.Escape:
                    Application.Exit();
                    break;
            }
        }
    }
}