Learn MONOGAME with Real Code Examples

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class CounterGame : Game
{
    private GraphicsDeviceManager _graphics;
    private SpriteBatch _spriteBatch;
    private SpriteFont _font;
    private int count = 0;

    public CounterGame() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }

    protected override void LoadContent() { _spriteBatch = new SpriteBatch(GraphicsDevice); _font = Content.Load<SpriteFont>("Arial"); }

    protected override void Update(GameTime gameTime)
    {
        var kstate = Keyboard.GetState();
        if (kstate.IsKeyDown(Keys.Up)) count++;
        if (kstate.IsKeyDown(Keys.Down)) count--;
        base.Update(gameTime);
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        _spriteBatch.Begin();
        _spriteBatch.DrawString(_font, $"Count: {count}", new Vector2(100, 100), Color.White);
        _spriteBatch.End();
        base.Draw(gameTime);
    }
}

A minimal MonoGame example displaying a counter that increments/decrements with keyboard input.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class SpriteMove : Game
{
    private GraphicsDeviceManager _graphics;
    private SpriteBatch _spriteBatch;
    private Texture2D _sprite;
    private Vector2 _position = new Vector2(100,100);
    private float _speed = 2f;

    public SpriteMove() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }

    protected override void LoadContent() { _spriteBatch = new SpriteBatch(GraphicsDevice); _sprite = Content.Load<Texture2D>("player"); }

    protected override void Update(GameTime gameTime)
    {
        var kstate = Keyboard.GetState();
        if (kstate.IsKeyDown(Keys.Left)) _position.X -= _speed;
        if (kstate.IsKeyDown(Keys.Right)) _position.X += _speed;
        if (kstate.IsKeyDown(Keys.Up)) _position.Y -= _speed;
        if (kstate.IsKeyDown(Keys.Down)) _position.Y += _speed;
        base.Update(gameTime);
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        _spriteBatch.Begin();
        _spriteBatch.Draw(_sprite, _position, Color.White);
        _spriteBatch.End();
        base.Draw(gameTime);
    }
}

Moves a texture sprite using arrow keys.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class FpsDisplay : Game
{
    private GraphicsDeviceManager _graphics;
    private SpriteBatch _spriteBatch;
    private SpriteFont _font;
    public FpsDisplay() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void LoadContent() { _spriteBatch = new SpriteBatch(GraphicsDevice); _font = Content.Load<SpriteFont>("Arial"); }
    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        _spriteBatch.Begin();
        int fps = (int)(1 / gameTime.ElapsedGameTime.TotalSeconds);
        _spriteBatch.DrawString(_font, $"FPS: {fps}", new Vector2(10,10), Color.White);
        _spriteBatch.End();
        base.Draw(gameTime);
    }
}

Displays frames per second on screen.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class AnimationExample : Game
{
    private GraphicsDeviceManager _graphics;
    private SpriteBatch _spriteBatch;
    private Texture2D _spriteSheet;
    private int _frame = 0;
    private double _timer = 0;
    private Vector2 _position = new Vector2(100,100);
    public AnimationExample() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void LoadContent() { _spriteBatch = new SpriteBatch(GraphicsDevice); _spriteSheet = Content.Load<Texture2D>("sprite_sheet"); }
    protected override void Update(GameTime gameTime)
    {
        _timer += gameTime.ElapsedGameTime.TotalSeconds;
        if (_timer > 0.1) { _frame = (_frame + 1) % 4; _timer = 0; }
        base.Update(gameTime);
    }
    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        _spriteBatch.Begin();
        _spriteBatch.Draw(_spriteSheet, _position, new Rectangle(32*_frame,0,32,32), Color.White);
        _spriteBatch.End();
        base.Draw(gameTime);
    }
}

Cycles through sprite frames to animate.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class KeyboardExample : Game
{
    private GraphicsDeviceManager _graphics;
    public KeyboardExample() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void Update(GameTime gameTime)
    {
        var kstate = Keyboard.GetState();
        if (kstate.IsKeyDown(Keys.Space)) { System.Console.WriteLine("Space pressed"); }
        base.Update(gameTime);
    }
}

Prints a message when keys are pressed.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class MouseExample : Game
{
    private GraphicsDeviceManager _graphics;
    public MouseExample() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void Update(GameTime gameTime)
    {
        var mstate = Mouse.GetState();
        if (mstate.LeftButton == ButtonState.Pressed) { System.Console.WriteLine("Left click"); }
        if (mstate.RightButton == ButtonState.Pressed) { System.Console.WriteLine("Right click"); }
        base.Update(gameTime);
    }
}

Detects left and right mouse clicks.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class PhysicsExample : Game
{
    private GraphicsDeviceManager _graphics;
    private SpriteBatch _spriteBatch;
    private Vector2 _position = new Vector2(100,0);
    private float _vspeed = 0;
    private float _gravity = 200f;
    public PhysicsExample() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void Update(GameTime gameTime)
    {
        _vs = _vspeed + _gravity * (float)gameTime.ElapsedGameTime.TotalSeconds;
        _position.Y += _vspeed * (float)gameTime.ElapsedGameTime.TotalSeconds;
        base.Update(gameTime);
    }
}

Applies simple gravity to a falling object.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class EnemyFollow : Game
{
    private GraphicsDeviceManager _graphics;
    private Vector2 _enemyPos = new Vector2(50,50);
    private Vector2 _playerPos = new Vector2(200,200);
    private float _speed = 2f;
    public EnemyFollow() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void Update(GameTime gameTime)
    {
        Vector2 dir = _playerPos - _enemyPos;
        dir.Normalize();
        _enemyPos += dir * _speed;
        base.Update(gameTime);
    }
}

Enemy moves towards player position each frame.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System.Collections.Generic;

public class ShootingExample : Game
{
    private GraphicsDeviceManager _graphics;
    private List<Vector2> bullets = new List<Vector2>();
    private Vector2 playerPos = new Vector2(100,100);
    public ShootingExample() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void Update(GameTime gameTime)
    {
        if (Keyboard.GetState().IsKeyDown(Keys.Space)) { bullets.Add(playerPos); }
        for(int i=0;i<bullets.Count;i++) { bullets[i] += new Vector2(5,0); }
        base.Update(gameTime);
    }
}

Player shoots bullets when pressing space.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

public class RandomWalker : Game
{
    private GraphicsDeviceManager _graphics;
    private Vector2 pos = new Vector2(100,100);
    private Random rnd = new Random();
    public RandomWalker() { _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; IsMouseVisible = true; }
    protected override void Update(GameTime gameTime)
    {
        pos.X += rnd.Next(-1,2);
        pos.Y += rnd.Next(-1,2);
        base.Update(gameTime);
    }
}

Moves a point randomly each frame.