保存到相册时，ALAssetsLibrary会询问用户是否有权限？为什么？

I have a game where users can take a screen shot and it will save it to a custom album named after the game. When I try and do this, iOS asks the user if the App can have access to their location information, if they say no, then the screen shot is not saved in the custom album, but rather the default album.I have a game where users can take a screen sho