|sceneBuildIndex||Build Settings 中的场景索引。|
AsyncOperation 使用 AsyncOperation 确定操作是否已完成。
销毁所有与给定场景关联的游戏对象，并将场景从 SceneManager 中移除。
The given Scene name can either be the full Scene path, the path
shown in the Build Settings window or just the Scene name. If only the Scene name
is given this will unload the first Scene in the list that matches. If you have
multiple Scenes with same name but different paths, you should use the full Scene path.
Examples of supported formats:
Note: This is case-insensitive and due to it being async there are no guarantees about completion time.
Note: Assets are currently not unloaded. In order to free up asset memory call Resources.UnloadAllUnusedAssets.