Unity2D宝箱功能bug：范围外按X进入范围后错误掉落道具求助

问题根因 #

• TouchingChestBoxCollider状态未正确重置：玩家离开宝箱触发范围后，该变量仍然保持为true，导致范围外按X也能触发xIsPressed赋值。同时OnTriggerStay2D中未判断碰撞对象就直接修改该变量，可能被其他碰撞体误触发。
• xIsPressed状态永久残留：该变量被赋值为true后没有任何重置逻辑，只要历史上有过一次在TouchingChestBoxCollider为true时按下X的操作，后续进入宝箱范围时就会直接触发掉落。即使之前是误触发的xIsPressed=true，状态也会一直保留。

修复方案 #

推荐方案（逻辑最贴合需求） #

利用xIsPressed仅需存活一帧的特性，每次Update结束后重置状态，从根源避免残留：

1. 修正TouchingChestBoxCollider的赋值与重置逻辑，仅玩家碰撞时修改状态
2. 在LateUpdate中重置xIsPressed为false，确保按下状态仅生效一帧
3. 优化OnTriggerStay2D的判断顺序，减少无效逻辑执行

修改后完整代码 #

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ChestOpener : MonoBehaviour
{
    [SerializeField]
    private GameObject ChestItSelf;

    [SerializeField]
    private GameObject[] itemsWeapon;

    [SerializeField]
    private GameObject[] itemsMedi;

    [SerializeField]
    private SpriteRenderer spriteRenderer;

    [SerializeField]
    private Sprite openSprite, closeSprite;

    private int random;
    private Vector2 destination;
    private GameObject objectsWeapon;
    private GameObject objectsWeapon2;
    private GameObject objectsMedi;
    private bool HasItDropped = false;
    private bool MoveItemNow = false;
    private bool xIsPressed = false;
    private bool TouchingChestBoxCollider = false;

    private void Update()
    {        
        if (Input.GetKeyDown(KeyCode.X)  && TouchingChestBoxCollider == true)
        {
            xIsPressed = true;
        }
        if (MoveItemNow == true )
        {
            objectsWeapon.transform.position = Vector2.Lerp(objectsWeapon.transform.position, new Vector2(transform.position.x, transform.position.y - 4), 
                Time.deltaTime * 1f);
            objectsWeapon2.transform.position = Vector2.Lerp(objectsWeapon2.transform.position, new Vector2(transform.position.x-2, transform.position.y - 4),
                Time.deltaTime * 1f);
        }  
    }

    // 新增LateUpdate，每帧结束重置X键按下状态，避免残留
    private void LateUpdate()
    {
        xIsPressed = false;
    }

    private void OnTriggerStay2D(Collider2D collision) 
    {
        // 仅处理玩家的碰撞事件
        if (collision.gameObject.tag != "Player") return;
        TouchingChestBoxCollider = true;
        if (HasItDropped == false && xIsPressed == true)
        {
            DropDownItem();
        }
    }
    private void DropDownItem()
    {
        spriteRenderer.sprite = openSprite;
        random = UnityEngine.Random.Range(0, itemsWeapon.Length);
        objectsWeapon = Instantiate(itemsWeapon[random], transform.position, Quaternion.identity);
        objectsWeapon2 = Instantiate(itemsWeapon[random], transform.position, Quaternion.identity);
        
        MoveItemNow = true; 
        HasItDropped = true;
    }
    private void OnTriggerExit2D(Collider2D collision)
    {
        // 仅玩家离开时重置触摸状态
        if (collision.gameObject.tag != "Player") return;
        TouchingChestBoxCollider = false;
        spriteRenderer.sprite = closeSprite;
        Invoke("FareWellChest", 2f);
       
    }
    private void FareWellChest()
    {
        if (HasItDropped == true)
        {
            Destroy(ChestItSelf);
        }
    } 
}

极简改法（改动量最小） #

如果不想新增LateUpdate，也可以仅修改3处逻辑即可解决问题：

1. OnTriggerStay2D中仅玩家碰撞时才给TouchingChestBoxCollider赋值为true
2. OnTriggerExit2D玩家离开时，同时重置TouchingChestBoxCollider和xIsPressed为false
3. DropDownItem执行完成后，重置xIsPressed为false

内容的提问来源于stack exchange，提问作者YuDotNet