为什么我在尝试获取预制资产路径时得到空字符串？

Question

 private void ModifyPrefab(GameObject child)
    {
        var mostPrefabInstanceRoot = PrefabUtility.GetOutermostPrefabInstanceRoot(child);

        // Get the Prefab Asset root GameObject and its asset path.
        string assetPath = AssetDatabase.GetAssetPath(mostPrefabInstanceRoot);

        // Load the contents of the Prefab Asset.
        GameObject contentsRoot = PrefabUtility.LoadPrefabContents(assetPath);

        // Modify Prefab contents.
        DestroyImmediate(child);

        // Save contents back to Prefab Asset and unload contents.
        PrefabUtility.SaveAsPrefabAsset(contentsRoot, assetPath);
        PrefabUtility.UnloadPrefabContents(contentsRoot);
    }

assetPath 为空“”

运行时第一个 mostPrefabInstanceRoot 是：“Room_Large_Windows_Part_03 (UnityEngine.GameObject)”

在编辑器中这个对象是一个预制件：

然后在预制件上右键单击并选择预制件资产时，它会到达：

但在脚本中字符串返回“”

我不明白为什么它返回空字符串？

现在编辑这是我完成的脚本：

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEngine;

public class ObjectsReplace : MonoBehaviour
{
    public GameObject prefabToInit;

    // Note your method should probably return something
    public void UpdateOrAddShaderPrefabToDoors()
    {
        GameObject[] doorsLeft = GameObject.FindGameObjectsWithTag("Door_Left");
        GameObject[] doorsRight = GameObject.FindGameObjectsWithTag("Door_Right");

        List<GameObject> allDoors = doorsLeft.Union(doorsRight).ToList();

        allDoors.ForEach(gameObject =>
        {
            Transform childTransform = gameObject.transform.Find("DoorShieldFXLocked Variant");
            GameObject child = childTransform?.gameObject;
            Debug.Log($"Child exist: {child != null}, Name of child: {child?.name}");
            if (child != null)
            {
                ModifyPrefab(child);
            }
        });
    }

    private void ModifyPrefab(GameObject child)
    {
        var mostPrefabInstanceRoot = PrefabUtility.GetOutermostPrefabInstanceRoot(child);

        // Get the Prefab Asset root GameObject and its asset path.
        string assetPath = PrefabUtility.GetPrefabAssetPathOfNearestInstanceRoot(mostPrefabInstanceRoot);

        // Load the contents of the Prefab Asset.
        GameObject contentsRoot = PrefabUtility.LoadPrefabContents(assetPath);

        // Modify Prefab contents.
        DestroyImmediate(child);

        // Save contents back to Prefab Asset and unload contents.
        PrefabUtility.SaveAsPrefabAsset(contentsRoot, assetPath);
        PrefabUtility.UnloadPrefabContents(mostPrefabInstanceRoot);
    }
}

但在尝试销毁孩子时仍然在编辑器中出现异常：

InvalidOperationException：不允许在 Prefab 实例中销毁 GameObject。

这个想法是打开它所属的子预制件以销毁子代，然后保存并关闭预制件，就像在编辑器中但从脚本中执行 Overrides > Apply Changes 一样。

Answer 1

看起来mostPrefabInstanceRoot 不是资产，这是有道理的，因为它是预制件的一个实例。使用PrefabUtility.GetPrefabAssetPathOfNearestInstanceRoot 而不是AssetDatabase.GetAssetPath。

string assetPath = PrefabUtility.GetPrefabAssetPathOfNearestInstanceRoot(mostPrefabInstanceRoot);

另外，为了使您的编辑生效，您可能希望保存 mostPrefabInstanceRoot 而不是 contentRoot，因为删除子项后 contentRoot 将保持不变。