该对象不保存到场景。加载新场景时，也不会销毁它。它是 HideFlags.DontSaveInBuild | HideFlags.DontSaveInEditor | HideFlags.DontUnloadUnusedAsset 的快捷方式。
You must manually apply the flag to the entire hierarchy of game objects you desire to affect. For Prefab instances in a scene, you can set the hideflag on the Prefab instance handle object as a way to set the same hideflags on all the objects of the Prefab instance. (See PrefabUtility.GetPrefabInstanceHandle).