unity 图集资源引用查找

图集使用TexturePacker打出来的，图集用的时间旧了，不确定哪些资源是被prefab引用，哪些是不需要用的，最近查看unity工具顺便写了个简单脚本，检测图集资源被prefab引用情况

原理很简单，图集中的每个子对象在引用的时候，都是通过fileId和guid进行关联的，

guid就是图集那个png资源文件的guid，一个图集包含多个sprite，图集中的每个sprite是没有guid的，只有fileID，可以在meta文件中查看

代码要做的就是先获取到图集资源的fileId和guid，然后便利prefab所在目录下所有prefab文件，查看prefab文件中是否包含图集的guid和fileID

代码如下

        public class AssetDataIfo
        {
            public long id;
            public string name;
            public Object obj;
        }

        [MenuItem("Assets/Atlas ReferenceViewer")]
        private static void Open()
        {
            var selectedObject = Selection.activeObject ;
            string path = AssetDatabase.GetAssetPath(selectedObject);
            string GUID = AssetDatabase.AssetPathToGUID(path);
            string searchFolder = "Assets/Prefab";
            string[] prefabGUIDs = AssetDatabase.FindAssets("t:Prefab", new string[] { searchFolder});
            foreach (var item in prefabGUIDs)
            {
                string itemPath = AssetDatabase.GUIDToAssetPath(item);
            }

            Debug.Log("select item path is " + path);
            Object[] objects = AssetDatabase.LoadAllAssetsAtPath(path);
            if (!path.EndsWith(".png") || objects.Length <= 1)
            {
                Debug.LogError("please select atlas png item");
                return;
            }
            AssetDataIfo info;
            //图集单个sprite信息字典
            int index = 0;
            foreach (var item in objects)
            {
                info = GetObjectLocalIdInFile(item);
                Debug.Log(string.Format("搜索sprite:{0}的引用信息：", info.name));
                EditorUtility.DisplayProgressBar("查找引用信息", info.name, index * 1.0f / objects.Length);
                foreach (var prefabPath in prefabGUIDs)
                {
                    string itemPath = AssetDatabase.GUIDToAssetPath(prefabPath);
                    SearchRefrence(info.id, GUID, itemPath);
                }
                index++;
            }
            EditorUtility.ClearProgressBar();

            //SelectObject(objDict[id]);
        }

        static void SelectObject(Object selectItem)
        {
            Selection.activeObject = selectItem;
            EditorGUIUtility.PingObject(selectItem);
        }

        static void SearchRefrence(long id, string guid, string prefabPath)
        {
            //Debug.Log("prefabPath is " + prefabPath);
            string searchText = string.Format("fileID: {0}, guid: {1}",id, guid);//id.ToString();
            string fullPath = Application.dataPath + prefabPath.Replace("Assets", "");
            string msg = File.ReadAllText(fullPath);
            int index = 0;
            int count = 0;
            while ((index = msg.IndexOf(searchText, index)) != -1)
            {
                count++;
                index = index + searchText.Length;
            }
            if (count > 0)
                Debug.Log(string.Format("\"{0}\"在prefab {1} 中出现第{2}次。", searchText, prefabPath, count));
            //else Debug.Log("引用次数为0");
        }