Alex教程每一P的教程原代码加上我自己的理解初步理解写的注释，可供学习Alex教程的人参考
此代码仅为较上一P有所改变的代码

【Unity教程】从0编程制作类银河恶魔城游戏_哔哩哔哩_bilibili

Enemy.cs

using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;public class Enemy : Entity
{[SerializeField] protected LayerMask whatIsPlayer;[Header("Move Info")]public float moveSpeed;public float idleTime;public float battleTime;//多久能从battle状态中退出来[Header("Attack Info")]public float attackDistance;public float attackCooldown;//攻击冷却[HideInInspector]public float lastTimeAttacked;//最后一次攻击的时间#region 类public EnemyStateMachine stateMachine;#endregionprotected override void Awake(){base.Awake();stateMachine = new EnemyStateMachine();}protected override void Start(){base.Start();}protected override void Update(){base.Update();stateMachine.currentState.Update();//Debug.Log(IsPlayerDetected().collider.gameObject.name + "I see");//这串代码会报错，可能使版本的物体，因为在没有找到Player的时候物体是空的，NULL，你想让他在控制台上显示就报错了}public virtual void AnimationFinishTrigger() => stateMachine.currentState.AnimationFinishTrigger();//动画完成时调用的函数，与Player相同public virtual RaycastHit2D IsPlayerDetected() => Physics2D.Raycast(wallCheck.position, Vector2.right * facingDir, 7, whatIsPlayer);//用于从射线投射获取信息的结构。//该函数的返回值可以变，可以只返回bool，也可以是碰到的结构protected override void OnDrawGizmos(){base.OnDrawGizmos();Gizmos.color = Color.yellow;Gizmos.DrawLine(transform.position, new Vector3(transform.position.x + attackDistance * facingDir, transform.position.y));}}

SkeletonGroundState.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class SkeletonGroundState : EnemyState
{protected Enemy_Skeleton enemy;protected Transform player;public SkeletonGroundState(Enemy _enemyBase, EnemyStateMachine _stateMachine, string _animBoolName,Enemy_Skeleton _enemy) : base(_enemyBase, _stateMachine, _animBoolName){enemy = _enemy;}public override void Enter(){base.Enter();player = GameObject.Find("Player").transform;}public override void Exit(){base.Exit();}public override void Update(){base.Update();if(enemy.IsPlayerDetected()||Vector2.Distance(enemy.transform.position,player.transform.position)<2){stateMachine.ChangeState(enemy.battleState);}}
}

SkeletonBattleState.cs

using System.Collections;
using System.Collections.Generic;
using TMPro;
using UnityEngine;
//从ground进来的
public class SkeletonBattleState : EnemyState
{private Transform player;//用于给Player定位，好判断怎么跟上他private Enemy_Skeleton enemy;private int moveDir;public SkeletonBattleState(Enemy _enemyBase, EnemyStateMachine _stateMachine, string _animBoolName,Enemy_Skeleton _enemy ) : base(_enemyBase, _stateMachine, _animBoolName){enemy = _enemy;}public override void Enter(){base.Enter();player = GameObject.Find("Player").transform;//全局找Player位置}public override void Exit(){base.Exit();}public override void Update(){base.Update();//退出此状态的方式if(enemy.IsPlayerDetected()){stateTimer = enemy.battleTime;if (enemy.IsPlayerDetected().distance < enemy.attackDistance)//当距离小于攻击距离，变为攻击状态{if (CanAttack())stateMachine.ChangeState(enemy.attackState);}}else//当没有看见player后，才会根据没有看到的时间来使其退出battle状态{if(stateTimer < 0||Vector2.Distance(player.transform.position,enemy.transform.position)>7)//根据距离来判断是否结束battle状态{stateMachine.ChangeState(enemy.idleState);}}//下面为移动方向设置if(player.position.x > enemy.transform.position.x)//在右，向右移动{moveDir = 1;}else if(player.position.x<enemy.transform.position.x)//在左，向左移动{moveDir = -1;}enemy.SetVelocity(enemy.moveSpeed * moveDir, rb.velocity.y);}private bool CanAttack(){if(Time.time > enemy.lastTimeAttacked + enemy.attackCooldown){enemy.lastTimeAttacked = Time.time;return true;}Debug.Log("Attack is on cooldown");return false;}
}