unity批量替换预制件内的脚本不丢失数据

批量替换unity中已存在的脚本，比如重命名，或者替换重复的脚本；

    [MenuItem("Assets/empty4替换")]
    public static void ScriptGuidChange()
    {
        StringBuilder sb = new StringBuilder();
        string oldGuid = "a93801baeef446cdb7503c9f0a1ecb7d";
        string newGuid = "179e7073a9e23b8439f037e9ca8f4323";
        string[] guids = AssetDatabase.FindAssets("t:prefab");
        foreach (var guid in guids)
        {
            var path = AssetDatabase.GUIDToAssetPath(guid);
            if (path.StartsWith("Assets"))
            {
                var file = File.OpenText(path);
                StringBuilder newStr = new StringBuilder();
                bool isNew = false;
                while (true)
                {
                    var str = file.ReadLine();
                    if (string.IsNullOrEmpty(str))
                    {
                        break;
                    }
                    else
                    {
                        if (str.Contains(oldGuid))
                        {
                            str = str.Replace(oldGuid, newGuid);
                            sb.AppendLine(path + "：" + str);
                            isNew = true;
                        }
                    }
                    newStr.AppendLine(str);
                }
                file.Close();
                file.Dispose();
                if (isNew)
                {
                    File.WriteAllText(path, newStr.ToString());
                }
            }
        }
        Debug.LogError(sb.ToString());
    }