Unity开发：调用Teleport()时如何获取敌人当前的enemyTransform.position？

触发OnTriggerEnter碰撞敌人时已保存enemyTransform，后续点击传送按钮执行Teleport()，希望传送到敌人的实时位置，但Teleport()内的enemyTransform始终为null，无法实现需求。

问题代码 #

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using ThrowOrbNamespace;

public class orbLogic : MonoBehaviour
{
    public ThrowOrbNamespace.ThrowOrb throwOrb;

    public Button teleportButton;

    public CharacterController characterController;

    private Transform enemyTransform;

    void Start()
    {
        teleportButton.interactable = false;
    }

    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Enemy"))
        {    
            enemyTransform = other.transform;

            throwOrb.StopAll();

            Destroy(gameObject);

            teleportButton.interactable = true;

            Debug.Log(enemyTransform.position); //enemyTransform != null
        }
    }

    public void Teleport()
    {
        Debug.Log(enemyTransform.position); //enemyTransform == null
        if (enemyTransform != null)
        {
            characterController.enabled = false;
            characterController.transform.position = enemyTransform.position;
            characterController.enabled = true;

            teleportButton.interactable = false;
        }
    }
}

问题原因 #

核心问题是OnTriggerEnter里的Destroy(gameObject);语句——这条代码会销毁挂载orbLogic脚本的游戏对象，脚本实例也会被销毁，导致之前保存的enemyTransform引用直接丢失，因此Teleport()执行时引用为null。

解决方案 #

方案1：移除销毁当前对象的代码 #

如果不需要销毁挂载脚本的对象，直接删除Destroy(gameObject);即可，这样enemyTransform的引用会一直保留，Teleport时就能获取敌人的实时位置：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using ThrowOrbNamespace;

public class orbLogic : MonoBehaviour
{
    public ThrowOrbNamespace.ThrowOrb throwOrb;

    public Button teleportButton;

    public CharacterController characterController;

    private Transform enemyTransform;

    void Start()
    {
        teleportButton.interactable = false;
    }

    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Enemy"))
        {    
            enemyTransform = other.transform;

            throwOrb.StopAll();

            // 移除销毁语句，保留脚本实例和引用
            // Destroy(gameObject);

            teleportButton.interactable = true;

            Debug.Log(enemyTransform.position);
        }
    }

    public void Teleport()
    {
        if (enemyTransform != null)
        {
            Debug.Log(enemyTransform.position);
            characterController.enabled = false;
            characterController.transform.position = enemyTransform.position;
            characterController.enabled = true;

            teleportButton.interactable = false;
        }
        else
        {
            Debug.LogWarning("未找到敌人Transform引用");
        }
    }
}

方案2：用全局管理器存储敌人引用（必须销毁当前对象时） #

如果业务逻辑要求必须销毁当前对象，需将敌人的引用转移到一个持久存在的全局脚本中，比如创建GameManager：

using UnityEngine;

public class GameManager : MonoBehaviour
{
    public static GameManager Instance;

    public Transform CurrentEnemyTransform { get; set; }

    void Awake()
    {
        // 确保管理器全局唯一且不被销毁
        if (Instance == null)
        {
            Instance = this;
            DontDestroyOnLoad(gameObject);
        }
        else
        {
            Destroy(gameObject);
        }
    }
}

修改orbLogic代码，将敌人引用存入全局管理器：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using ThrowOrbNamespace;

public class orbLogic : MonoBehaviour
{
    public ThrowOrbNamespace.ThrowOrb throwOrb;

    public Button teleportButton;

    public CharacterController characterController;

    void Start()
    {
        teleportButton.interactable = false;
    }

    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Enemy"))
        {    
            // 将敌人引用存入全局管理器
            GameManager.Instance.CurrentEnemyTransform = other.transform;

            throwOrb.StopAll();

            Destroy(gameObject); // 现在可以安全销毁当前对象

            teleportButton.interactable = true;

            Debug.Log(other.transform.position);
        }
    }

    public void Teleport()
    {
        var enemyTransform = GameManager.Instance.CurrentEnemyTransform;
        if (enemyTransform != null)
        {
            Debug.Log(enemyTransform.position);
            characterController.enabled = false;
            characterController.transform.position = enemyTransform.position;
            characterController.enabled = true;

            teleportButton.interactable = false;
            // 传送完成后清空引用
            GameManager.Instance.CurrentEnemyTransform = null;
        }
        else
        {
            Debug.LogWarning("未找到敌人Transform引用");
        }
    }
}

内容的提问来源于stack exchange，提问作者Ilya