Monogame make objects in class move independently

Question

I have a problem with my code. I am trying to make 2000 blocks bounce on the screen. I have made it work with one block but when I add more the x and y-axis update on all of them as soon as one of them hit the borders at the edge of the screen. So I want all objects x and y axises to update independently and not move together as they're doing right now. Here is my code:

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

namespace Project_blob
{
public class Game1 : Game
{
    private GraphicsDeviceManager _graphics;
    private SpriteBatch _spriteBatch;
    Texture2D pixelTexture;
    List<Block> blocks = new List<Block>();
    Block block;
    int speed1 = 1;
    int speed2 = -1;
    



    public Game1()
    {
        _graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";
        IsMouseVisible = true;
    }

    protected override void Initialize()
    {
        
        Random rnd = new Random();
        // TODO: Add your initialization logic here

        block = new Block();
        for (int i = 0; i < 2000; i++)
        {
            var block = new Block();
            block.X = rnd.Next(0, 780);
            block.Y = rnd.Next(0, 500);
            block.Color = new Color(rnd.Next(256), rnd.Next(256), rnd.Next(256));
            blocks.Add(block);
            

        }
        base.Initialize();
    }

    protected override void LoadContent()
    {
        _spriteBatch = new SpriteBatch(GraphicsDevice);
        pixelTexture = Content.Load<Texture2D>("pixel");
        // TODO: use this.Content to load your game content here
    }

    protected override void Update(GameTime gameTime)
    {
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
            Exit();

        foreach (Block block in blocks)
        {
            if (block.X < 0) speed2 += 1;
            if (block.X > 770) speed2 += -1;
            if (block.Y > 450) speed1 += -1;
            if (block.Y < 0) speed1 += 1;
            if (speed1 < -1) speed1 = -1;
            if (speed1 > 1) speed1 = 1;
            if (speed2 < -1) speed2 = -1;
            if (speed2 > 1) speed2 = 1;
            block.X += speed2;
            block.Y += speed1;
        }

        base.Update(gameTime);
        
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);

        _spriteBatch.Begin();
        foreach (Block block in blocks)
        {
            block.Draw(_spriteBatch, pixelTexture);
        }
        _spriteBatch.End();

        base.Draw(gameTime);
    }
}
}

and then Block.cs

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

namespace Project_blob
 {
 public class Block
{
        public int X { get; set; } = 100;
        public int Y { get; set; } = 100;
        public Color Color { get; set; } = Color.Red;
        public int speed1 = 1;
        public int speed2 = -1;

   
   


    public void Draw(SpriteBatch spriteBatch, Texture2D texture)
        {
            spriteBatch.Draw(texture, new Rectangle(X, Y, 30, 30), Color);
        }
    
}
}

Would be thankful if you were to help me in my project.

Answer 1

I would recommend putting them in a personal Update() class. They'll need to make use of their local speed1 and speed2 variables, and the global speed1 and speed2 in the game1.cs should be removed to avoid confusion.

Something like this:

in game1.cs:

protected override void Update(GameTime gameTime)
{
    if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
        Exit();

    foreach (Block block in blocks)
    {
        block.Update();
    }

    base.Update(gameTime);
    
}

In Block.cs:

public void Update()
{
    if (X < 0) speed2 += 1;
    if (X > 770) speed2 += -1;
    if (Y > 450) speed1 += -1;
    if (Y < 0) speed1 += 1;
    if (speed1 < -1) speed1 = -1;
    if (speed1 > 1) speed1 = 1;
    if (speed2 < -1) speed2 = -1;
    if (speed2 > 1) speed2 = 1;
    X += speed2;
    Y += speed1;
}

Answer 2

You have global variables for speed1 and speed2 in your game, where I think you're trying to calculate these for each individual block. Just make them local in the loop and reset them each iteration

 foreach (Block block in blocks)
 {
    var speed1 = 1;
    var speed2 = -1;
    if (block.X < 0) speed2 += 1;
    if (block.X > 770) speed2 += -1;
    if (block.Y > 450) speed1 += -1;
    if (block.Y < 0) speed1 += 1;
    if (speed1 < -1) speed1 = -1;
    if (speed1 > 1) speed1 = 1;
    if (speed2 < -1) speed2 = -1;
    if (speed2 > 1) speed2 = 1;
    block.X += speed2;
    block.Y += speed1;
 }