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

Entity.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class Entity : MonoBehaviour
{[Header("Collision Info")]public Transform attackCheck;//transform类，代表的时物体的位置,用来控制攻击检测的位置public float attackCheckRadius;//检测半径[SerializeField] protected Transform groundCheck;//transform类，代表的时物体的位置,后面会来定位子组件的位置    [SerializeField] protected float groundCheckDistance;[SerializeField] protected Transform wallCheck;//transform类，代表的时物体的位置,后面会来定位子组件的位置    [SerializeField] protected float wallCheckDistance;[SerializeField] protected LayerMask whatIsGround;//LayerMask类，与Raycast配合，https://docs.unity3d.com/cn/current/ScriptReference/Physics.Raycast.html#region 定义Unity组件public Animator anim { get; private set; }//这样才能配合着拿到自己身上的animator的控制权public Rigidbody2D rb { get; private set; }//配合拿到身上的Rigidbody2D组件控制权#endregionpublic int facingDir { get; private set; } = 1;protected bool facingRight = true;//判断是否朝右protected virtual void Awake(){anim = GetComponentInChildren<Animator>();//拿到自己身上的animator的控制权rb = GetComponent<Rigidbody2D>();}protected virtual void Start(){}protected virtual void Update(){}public virtual void Damage(){Debug.Log(gameObject.name+"was damaged");}#region 速度函数Velocitypublic virtual void SetZeroVelocity(){rb.velocity = new Vector2(0, 0);}//设置速度为0函数public virtual void SetVelocity(float _xVelocity, float _yVelocity){rb.velocity = new Vector2(_xVelocity, _yVelocity);//将rb的velocity属性设置为对应的想要的二维向量。因为2D游戏的速度就是二维向量FlipController(_xVelocity);//在其他设置速度的时候调用翻转控制器}//控制速度的函数，此函数在其他State中可能会使用，但仅能通过player.SeVelocity调用#endregion#region 翻转函数Flippublic virtual void Flip(){facingDir = facingDir * -1;facingRight = !facingRight;transform.Rotate(0, 180, 0);//旋转函数,transform不需要额外定义，因为他是自带的}//翻转函数public virtual void FlipController(float _x)//目前设置x，目的时能在空中时也能转身{if (_x > 0 && !facingRight)//当速度大于0且没有朝右时，翻转{Flip();}else if (_x < 0 && facingRight){Flip();}}#endregion#region 碰撞函数Collisionpublic virtual bool IsGroundDetected(){return Physics2D.Raycast(groundCheck.position, Vector2.down, groundCheckDistance, whatIsGround);}//通过RayCast检测是否挨着地面,https://docs.unity3d.com/cn/current/ScriptReference/Physics2D.Raycast.html//xxxxxxxx()   => xxxxxxxx  == xxxxxxxxxx() return xxxxxxxxx;public virtual bool IsWallDetected(){return Physics2D.Raycast(wallCheck.position, Vector2.right * facingDir, wallCheckDistance, whatIsGround);}//通过RayCast检测是否挨着地面,https://docs.unity3d.com/cn/current/ScriptReference/Physics2D.Raycast.html//xxxxxxxx()   => xxxxxxxx  == xxxxxxxxxx() return xxxxxxxxx;protected virtual void OnDrawGizmos(){Gizmos.DrawLine(groundCheck.position, new Vector3(groundCheck.position.x, groundCheck.position.y - groundCheckDistance));//绘制一条从 from(前面的) 开始到 to（后面的） 的线。Gizmos.DrawLine(wallCheck.position, new Vector3(wallCheck.position.x + wallCheckDistance, wallCheck.position.y));//绘制一条从 from(前面的) 开始到 to（后面的） 的线。Gizmos.DrawWireSphere(attackCheck.position, attackCheckRadius);//https://docs.unity3d.com/2022.3/Documentation/ScriptReference/Gizmos.DrawWireSphere.html//绘制具有中心和半径的线框球体。}//画图函数#endregion
}

PlayerAnimationTrigger.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class playerAnimationTriggers : MonoBehaviour
{private Player player => GetComponentInParent<Player>();//获得夫组件上的实际存在的Player组件private void AnimationTrigger(){player.AnimationTrigger();}private void AttackTrigger(){Collider2D[] colliders = Physics2D.OverlapCircleAll(player.attackCheck.position, player.attackCheckRadius);//创建一个碰撞器组，保存所有圈所碰到的碰撞器//https://docs.unity3d.com/2022.3/Documentation/ScriptReference/Physics2D.OverlapCircleAll.htmlforeach(var hit in colliders)//https://blog.csdn.net/m0_52358030/article/details/121722077{if(hit.GetComponent<Enemy>()!=null){hit.GetComponent<Enemy>().Damage();}}}
}

Enemy_SkeletonAnimationTrigger.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class Enemy_SkeletonAnimationTriggers : MonoBehaviour
{private Enemy_Skeleton enemy => GetComponentInParent<Enemy_Skeleton>();//拿到enemy实体private void AnimationTrigger(){enemy.AnimationFinishTrigger();//调用实体上的函数，使triggerCalled为true；}private void AttackTrigger(){Collider2D[] colliders = Physics2D.OverlapCircleAll(enemy.attackCheck.position, enemy.attackCheckRadius);//创建一个碰撞器组，保存所有圈所碰到的碰撞器//https://docs.unity3d.com/2022.3/Documentation/ScriptReference/Physics2D.OverlapCircleAll.htmlforeach (var hit in colliders)//https://blog.csdn.net/m0_52358030/article/details/121722077{if (hit.GetComponent<Player>() != null){hit.GetComponent<Player>().Damage();}}}
}

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;}if(Vector2.Distance(player.transform.position,enemy.transform.position)>1)enemy.SetVelocity(enemy.moveSpeed * moveDir, rb.velocity.y);else{enemy.SetZeroVelocity();}//我自己设置了一个敌人接近一定距离就停下来的设置，防止出现敌人乱晃的情况}private bool CanAttack(){if(Time.time > enemy.lastTimeAttacked + enemy.attackCooldown){enemy.lastTimeAttacked = Time.time;return true;}return false;}
}