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

Sword_Skill_Controller.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class Sword_Skill_Controller : MonoBehaviour
{[SerializeField] private float returnSpeed = 12;private bool isReturning;private Animator anim;private Rigidbody2D rb;private CircleCollider2D cd;private Player player;private bool canRotate = true;public float bounceSpeed;//设置弹跳速度public bool isBouncing = true;//判断是否可以弹跳public int amountOfBounce = 4;//弹跳的次数public List<Transform> enemyTargets;//保存所有在剑范围内的敌人的列表private int targetIndex;//设置targetIndex作为敌人计数器private void Awake(){anim = GetComponentInChildren<Animator>();rb = GetComponent<Rigidbody2D>();cd = GetComponent<CircleCollider2D>();}public void ReturnSword(){rb.constraints = RigidbodyConstraints2D.FreezeAll;//修复剑只要不触碰到物体就无法收回的bug//rb.isKinematic = false;transform.parent = null;isReturning = true;}public void SetupSword(Vector2 _dir,float _gravityScale,Player _player){player = _player;rb.velocity = _dir;rb.gravityScale = _gravityScale;anim.SetBool("Rotation", true);}private void Update(){if(canRotate)transform.right = rb.velocity;//使武器随着速度而改变朝向if (isReturning){transform.position = Vector2.MoveTowards(transform.position, player.transform.position, returnSpeed * Time.deltaTime);//从原来的位置返回到player的位置//并且随着时间增加而增加速度if(Vector2.Distance(transform.position,player.transform.position)<1)//当剑与player的距离小于一定距离，清除剑{player.CatchTheSword();}}                if(isBouncing && enemyTargets.Count > 0){transform.position = Vector2.MoveTowards(transform.position, enemyTargets[targetIndex].position,bounceSpeed*Time.deltaTime);//3.当可以弹跳且列表内数量大于0，调用ToWords,这将使剑能够跳到敌人身上if (Vector2.Distance(transform.position, enemyTargets[targetIndex].position)<.1f){targetIndex++;amountOfBounce--;//设置弹跳次数if (amountOfBounce <= 0){isBouncing = false;isReturning = true;}//这样会使当弹跳次数为0时，返回到角色手中if (targetIndex >= enemyTargets.Count){targetIndex = 0;}}//利用与目标距离的判断，使剑接近目标距离时切换到下一个目标。//且如果所有目标都跳完了，切回第一个}}private void OnTriggerEnter2D(Collider2D collision)//传入碰到的物体的碰撞器{if (isReturning){return;}//修复在返回时扔出时没有碰到任何物体，但返回时碰到了物体导致剑的一些性质发生改变的问题，及回来的时候调用了OnTriggerEnter2Dif (collision.GetComponent<Enemy>() != null)//首先得碰到敌人，只有碰到敌人才会跳{if (isBouncing && enemyTargets.Count <= 0){Collider2D[] colliders = Physics2D.OverlapCircleAll(transform.position, 10);foreach (var hit in colliders){if (hit.GetComponent<Enemy>() != null){enemyTargets.Add(hit.transform);}}}}StuckInto(collision);}//打开IsTrigger时才可使用该函数//https://docs.unity3d.com/cn/current/ScriptReference/Collider2D.OnTriggerEnter2D.htmlprivate void StuckInto(Collider2D collision){canRotate = false;cd.enabled = false;//相当于关闭碰撞后触发函数。//https://docs.unity3d.com/cn/current/ScriptReference/Collision2D-enabled.htmlrb.isKinematic = true;//开启物理学反应 https://docs.unity3d.com/cn/current/ScriptReference/Rigidbody2D-isKinematic.htmlrb.constraints = RigidbodyConstraints2D.FreezeAll;//冻结所有移动if (isBouncing&&enemyTargets.Count>0)//修复剑卡不到墙上的bugreturn;//终止对动画的改变和终止附在敌人上transform.parent = collision.transform;//设置sword的父组件为碰撞到的物体anim.SetBool("Rotation", false);}}