敌人不会产卵

Question

我对monogame很新，而且我遇到了另一个我无法理解的问题。经过一些其他问题（这些问题已由你们解决了！）我已经遇到了另一个问题！

我似乎无法弄清楚为什么我的小怪会产生，其他一切产生并按原样运作，但敌人不会产卵。我对此比较陌生，所以我没有尝试过任何东西，只是在网上查看教程，看看我是否正确完成了但是我看不出我做错了什么。

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

namespace Roid_shoooota
{

    public class Game1 : Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        //player and BG stuff
        PlayerShip Player = new PlayerShip();
        Background bG = new Background();

        //asteroid stuff
        List<Roids> asteroidList = new List<Roids>();
        Random random = new Random();

        //mob stuff
        public int enemyBulletDamage;
        List<Mobs> mobsList = new List<Mobs>();


        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
            graphics.IsFullScreen = false;
            graphics.PreferredBackBufferWidth = 800;
            graphics.PreferredBackBufferHeight = 950;
            this.Window.Title = "Roid Shoota";
            enemyBulletDamage = 10;
        }


        protected override void Initialize()
        {
            base.Initialize();
        }


        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);
            Player.LoadContent(Content);
            bG.LoadContent(Content);
        }

        protected override void UnloadContent()
        {
        }


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

            //updating mobs and checking for collisions
            foreach (Mobs M in mobsList)
            {
                if (M.hitBox.Intersects(Player.boundingBox))
                {
                    Player.health -= 40;
                    M.isVisible = false;
                }

                //enemy bullet collision with player
                for (int i = 0; i < M.bulletList.Count; i++)
                {
                    if (Player.boundingBox.Intersects(M.bulletList[i].hitBox))
                    {
                        Player.health -= enemyBulletDamage;
                        M.bulletList[i].isVisible = false;
                    }
                }


                for (int i = 0; i < Player.bulletList.Count; i++)
                {
                    if (Player.bulletList[i].hitBox.Intersects(M.hitBox))
                    {
                        Player.bulletList[i].isVisible = false;
                        M.isVisible = false;
                    }
                }
                M.update(gameTime);
            }

            //updating the asteroid list, check for collisions
            foreach (Roids R in asteroidList)
            {
                //if a roid hits the player get oot me game
                if (R.hitBox.Intersects(Player.boundingBox))
                {
                    Player.health -= 20;
                    R.isVisible = false;
                }

                for (int i = 0; i < Player.bulletList.Count; i++)
                {
                    if (R.hitBox.Intersects(Player.bulletList[i].hitBox))
                    {
                        R.isVisible = false;
                        Player.bulletList.ElementAt(i).isVisible = false;
                    }
                }
                R.update(gameTime);
            }

            Player.update(gameTime);
            bG.update(gameTime);
            loadAsteroids();
            loadMobs();

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            bG.Draw(spriteBatch);
            Player.draw(spriteBatch);

            foreach (Roids R in asteroidList)
            {
                R.Draw(spriteBatch);
            }


            foreach (Mobs M in mobsList)
            {
                M.Draw(spriteBatch);
            }

            spriteBatch.End();
            base.Draw(gameTime);
        }

        //random roid spawns
        public void loadAsteroids()
        {
            int randY = random.Next(-600, -50);
            int randX = random.Next(0, 750);

           //create more if less than 5
            if(asteroidList.Count() < 40)
            {
                asteroidList.Add(new Roids(Content.Load<Texture2D>("asteroid"), new Vector2(randX, randY)));
            }
            //if destoryed or off screen remove it from da list
            for (int i = 0; i < asteroidList.Count; i++)
            {
                if (!asteroidList[i].isVisible)
                {
                    asteroidList.RemoveAt(i);
                    i--;
                }
            }
        }

        //load mobs
        public void loadMobs()
        {
            int randY = random.Next(-600, -50);
            int randX = random.Next(0, 750);

            //create more if less than 3
            if (mobsList.Count() < 3)
            {
                mobsList.Add(new Mobs(Content.Load<Texture2D>("enemyship"), new Vector2(randX, randY), Content.Load<Texture2D>("EnemyBullet")));
            }
            //if destoryed or off screen remove it from da list
            for (int i = 0; i < mobsList.Count; i++)
            {
                if (!mobsList[i].isVisible)
                {
                    mobsList.RemoveAt(i);
                    i--;
                }
            }
        }
    }

}