Yes和No.普通用户将无法将其删除，但有根的手机用户，谁不知道他们在做什么。 ......那是一个不同的情况。

Yes and No. A normal user would not be able to delete them, but a user on a rooted phone who doesn't know what they're doing... thats a different situation.

如果你问我额外的code是不需要​​的。此外，如果你尝试不存在，你会得到扔在某些时候异常开放的文件，赶上并显示一个对话框，如果你真的想。

If you ask me the extra code is not needed. Also if you try an open a file that doesn't exist you will get an exception thrown at some point, catch that and display a dialog if you REALLY want to.