Full Source for the Parallax Scrolling Endless Runner Game

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

using System.Windows.Threading; // add this for the timer

namespace Endless_Runner_Game
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {

        // create a new instance of the dispatcher timer class called gametimer
        DispatcherTimer gameTimer = new DispatcherTimer();

        // create three new Rect class instance called player hit box and ground hit box and obstacle hit box
        Rect playerHitBox;
        Rect groundHitBox;
        Rect obstacleHitBox;

        // create a new boolean called jumping, by default this will set to false
        bool jumping;
        // make a new integer called force and set the value to 20
        int force = 20;
        // make another integer called speed and set the value to 5
        int speed = 5;
        // create a new instance of the random class called rand
        Random rand = new Random();
        // game over boolean
        bool gameover = false;
        // make a sprite int double variable, this will be used to swap the sprites for player
        double spriteInt = 0;

        // make three image brush instances called player sprite, background sprite and obstacle sprite
        ImageBrush playerSprite = new ImageBrush();
        ImageBrush backgroundSprite = new ImageBrush();
        ImageBrush obstacleSprite = new ImageBrush();

        //integer array which we will use to change the obstacle position on screen
        int[] obstaclePosition = { 320, 310, 300, 305, 315 };
        // empty integer called score
        int score = 0;

        public MainWindow()
        {
            InitializeComponent();

            //set the focus on my canvas from the WPF
            myCanvas.Focus();

            // assign the game engine event to the game timer tick
            gameTimer.Tick += gameEngine;
            // set the game timer interval to 20 milliseconds
            gameTimer.Interval = TimeSpan.FromMilliseconds(20);

            // first set the background sprite image
            backgroundSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/background.gif"));
            // add the background sprite to both rectangles
            background.Fill = backgroundSprite;
            background2.Fill = backgroundSprite;
            // run the start game function
            StartGame();

        }

        private void Canvas_KeyDown(object sender, KeyEventArgs e)
        {
            // if the game over boolean is true and the enter key is pressed
            if (e.Key == Key.Enter && gameover)
            {
                // run the start game function
                StartGame();
            }
        }

        private void Canvas_KeyUp(object sender, KeyEventArgs e)
        {
            // if the space key is pressed AND jumping boolean is true AND player y location is above 260 pixels
            if (e.Key == Key.Space && !jumping && Canvas.GetTop(player) > 260)
            {
                // set jumping to true
                jumping = true;
                // set force integer to 15
                force = 15;
                // set speed integer to -12
                speed = -12;
                // change the player sprite so it looks like he's jumping
                playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_02.gif"));
            }

        }

        private void StartGame()
        {
            // this is the start game function

            Canvas.SetLeft(background, 0); // set the first background to 0
            Canvas.SetLeft(background2, 1262); // set the second background to 1262

            // set the player x to 110 and y to 140
            Canvas.SetLeft(player, 110);
            Canvas.SetTop(player, 140);

            // set the obstacle x to 950 and y to 310
            Canvas.SetLeft(obstacle, 950);
            Canvas.SetTop(obstacle, 310);
            // set run sprite function to 1
            runSprite(1);

            // set the obstacle sprite, load the image from the images folder
            obstacleSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/obstacle.png"));
            obstacle.Fill = obstacleSprite; // assign the obstacle sprite to the obstacle object 

            // set jumping to false
            jumping = false;
            // set game over to false
            gameover = false;
            // set score to 0
            score = 0;
            // set the score text to the score integer
            scoreText.Content = "Score: " + score;

            // start the game timer
            gameTimer.Start();
        }

        private void runSprite(double i)
        {
            // this is the run sprite function, this function takes one argument inside its brackets
            // it takes a double variable called i
            // we will use this i to change the images for the player

            // below is the switch statement that will change the player sprite
            // when the i value changes between 1 and 8 it will assign appropriate sprite to the player sprite
            switch (i)
            {

                case 1:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_01.gif"));
                    break;
                case 2:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_02.gif"));
                    break;
                case 3:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_03.gif"));
                    break;
                case 4:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_04.gif"));
                    break;
                case 5:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_05.gif"));
                    break;
                case 6:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_05.gif"));
                    break;
                case 7:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_07.gif"));
                    break;
                case 8:
                    playerSprite.ImageSource = new BitmapImage(new Uri("pack://application:,,,/images/newRunner_08.gif"));
                    break;

            }
            // finally assign the player rectangle to the player sprite
            player.Fill = playerSprite;
        }

        private void gameEngine(object sender, EventArgs e)
        {
            // move the player character down using the speed integer
            Canvas.SetTop(player, Canvas.GetTop(player) + speed);
            // move the background 3 pixels to the left each tick
            Canvas.SetLeft(background, Canvas.GetLeft(background) - 3);
            Canvas.SetLeft(background2, Canvas.GetLeft(background2) - 3);
            // move the obstacle rectangle to the left 12 pixels per tick
            Canvas.SetLeft(obstacle, Canvas.GetLeft(obstacle) - 12);
            // link the score text label to the score integer
            scoreText.Content = "Score: " + score;

            // assign the player hit box to the player, gound hit box to the ground rectangle and obstacle hit box to the obstacle rectangle
            playerHitBox = new Rect(Canvas.GetLeft(player), Canvas.GetTop(player), player.Width, player.Height);
            groundHitBox = new Rect(Canvas.GetLeft(ground), Canvas.GetTop(ground), ground.Width, ground.Height);
            obstacleHitBox = new Rect(Canvas.GetLeft(obstacle), Canvas.GetTop(obstacle), obstacle.Width, obstacle.Height);

            // check player and ground collision
            // IF player hits the ground 
            if (playerHitBox.IntersectsWith(groundHitBox))
            {
                //if the player is on the ground set the speed to 0
                speed = 0;
                // place the character on top of the ground rectangle
                Canvas.SetTop(player, Canvas.GetTop(ground) - player.Height);
                // set jumping to false
                jumping = false;
                // add .5 to the sprite int double
                spriteInt += .5;
                // if the sprite int goes above 8
                if (spriteInt > 8)
                {
                    // reset the sprite int to 1
                    spriteInt = 1;
                }
                // pass the sprite int values to the run sprite function
                runSprite(spriteInt);
            }

            //if the player hit the obstacle
            if (playerHitBox.IntersectsWith(obstacleHitBox))
            {
                // set game over boolean to true
                gameover = true;
                // stop the game timer
                gameTimer.Stop();

            }

            //if jumping boolean is true
            if (jumping)
            {
                // set speed integer to -9 so the player will go upwards
                speed = -9;
                // reduce the force integer
                force--;
            }
            else
            {
                // if jumping is not true then set speed to 12
                speed = 12;
            }

            // if force is less than 0 
            if (force < 0)
            {
                // set jumping boolean to false
                jumping = false;
            }

            // parallax scrolling code for c#
            // the code below will scroll the background simlutaniously and make it seem endless

            // check the first background
            // if the first background X position goes below -1262 pixels
            if (Canvas.GetLeft(background) < -1262)
            {
                // position the first background behind the second background
                // below we are setting the backgrounds left, to background2 width position
                Canvas.SetLeft(background, Canvas.GetLeft(background2) + background2.Width);
            }
            // we do the same for the background 2
            // if background 2 X position goes below -1262
            if (Canvas.GetLeft(background2) < -1262)
            {
                // position the second background behind the first background
                // below we are setting background 2s left position or X position to backgrounds width position
                Canvas.SetLeft(background2, Canvas.GetLeft(background) + background.Width);
            }

            // if the obstacle goes beyond -50 location
            if (Canvas.GetLeft(obstacle) < -50)
            {
                // set the left position of the obstacle to 950 pixels
                Canvas.SetLeft(obstacle, 950);
                // randomly set the top positio of the obstacle from the array we created earlier
                // this will randomly pick a position from the array so it won't be the same each time it comes around the screen
                Canvas.SetTop(obstacle, obstaclePosition[rand.Next(0, obstaclePosition.Length)]);
                // add 1 to the score
                score += 1;
            }

            // if the game over boolean is set to true
            if (gameover)
            {
                // draw a black border around the obstacle
                // and set the border size to 1 pixel
                obstacle.Stroke = Brushes.Black;
                obstacle.StrokeThickness = 1;

                // draw a red border around the player
                // and set the border size to 1 pixel
                player.Stroke = Brushes.Red;
                player.StrokeThickness = 1;
                // add the following to the existing score text label
                scoreText.Content += "   Press Enter to retry";
            }
            else
            {
                // if the game is not order then reset the border thickness to 0 pixel
                player.StrokeThickness = 0;
                obstacle.StrokeThickness = 0;
            }
        }

    }
}

Make sure you have checked the spelling of the variables and objects to match your XAML Window, sometimes it can cause issues where if the objects are spelled differently it will not recognize it in the C# Script Window.