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")][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(){}#region 速度函数Velocitypublic virtual void ZeroVelocity(){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/Physics.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/Physics.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。}//画线函数#endregion
}

 Player.cs

using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;public class Player : Entity
{[Header("Attack Details")]public Vector2[] attackMovement;//每个攻击时获得的速度组public bool isBusy{ get; private set; }//防止在攻击间隔中进入move//[Header("Move Info")]public float moveSpeed;//定义速度，与xInput相乘控制速度的大小public float jumpForce;[Header("Dash Info")][SerializeField] private float dashCooldown;private float dashUsageTimer;//为dash设置冷却时间，在一定时间内不能连续使用public float dashSpeed;//冲刺速度public float dashDuration;//持续时间public float dashDir { get; private set; }#region 定义Statespublic PlayerStateMachine stateMachine { get; private set; }public PlayerIdleState idleState { get; private set; }public PlayerMoveState moveState { get; private set; }public PlayerJumpState jumpState { get; private set; }public PlayerAirState airState { get; private set; }public PlayerDashState dashState { get; private set; }public PlayerWallSlideState wallSlide { get; private set; }public PlayerWallJumpState wallJump { get; private set; }public PlayerPrimaryAttackState primaryAttack { get; private set; }#endregionprotected override void Awake(){base.Awake();stateMachine = new PlayerStateMachine();//通过构造函数，在构造时传递信息idleState = new PlayerIdleState(this, stateMachine, "Idle");moveState = new PlayerMoveState(this, stateMachine, "Move");jumpState = new PlayerJumpState(this, stateMachine, "Jump");airState = new PlayerAirState(this, stateMachine, "Jump");dashState = new PlayerDashState(this, stateMachine, "Dash");wallSlide = new PlayerWallSlideState(this, stateMachine, "WallSlide");wallJump = new PlayerWallJumpState(this, stateMachine, "Jump");//wallJump也是Jump动画primaryAttack = new PlayerPrimaryAttackState(this, stateMachine, "Attack");//this 就是 Player这个类本身}//Awake初始化所以State，为所有State传入各自独有的参数，及animBool，以判断是否调用此动画（与animatoin配合完成）protected override void Start(){base.Start();stateMachine.Initialize(idleState);}protected override void Update()//在mano中update会自动刷新但其他没有mano的不会故，需要在这个updata中调用其他脚本中的函数stateMachine.currentState.update以实现 //stateMachine中的update{base.Update();stateMachine.currentState.Update();//反复调用CurrentState的Update函数CheckForDashInput();}public IEnumerator BusyFor(float _seconds)//https://www.zhihu.com/tardis/bd/art/504607545?source_id=1001{isBusy = true;yield return new WaitForSeconds(_seconds);isBusy = false;}//p39 4.防止在攻击间隔中进入move,通过设置busy值，在使用某些状态时，使其为busy为true，抑制其进入其他state//IEnumertor本质就是将一个函数分块执行，只有满足某些条件才能执行下一段代码，此函数有StartCoroutine调用public void AnimationTrigger() => stateMachine.currentState.AnimationFinishTrigger();//从当前状态拿到AnimationTrigger进行调用的函数public void CheckForDashInput(){dashUsageTimer -= Time.deltaTime;//给dash上冷却时间if (IsWallDetected()){return;}//修复在wallslide可以dash的BUGif (Input.GetKeyDown(KeyCode.LeftShift) && dashUsageTimer < 0){dashUsageTimer = dashCooldown;dashDir = Input.GetAxisRaw("Horizontal");//设置一个值，可以将dash的方向改为你想要的方向而不是你的朝向if (dashDir == 0){dashDir = facingDir;//只有当玩家没有控制方向时才使用默认朝向}stateMachine.ChangeState(dashState);}}//将Dash切换设置成一个函数，使其在所以情况下都能使用}