问题:

I'm working on books library in my android app... so I want to add a functionality that allows the user to view the books that he/she has downloaded by my app..

any idea or hint to work this out?

回答1:

The final solution depends a bit on the details you want to store for the books. If you only want to store the book title and author and you don't want to deal with a database yet then SharedPreferences might be an option. But they are more like Java Properties files and with this said not a good solution for persisting more complex data structures.

If you want to store more metadata of the books (e.g. the current read position, bookmarks, etc.) then you will need a database sooner or later. I recommend thinking about the data model first and then start with the SQLite database included in Android.

You can find more details here Android Developers - Data Storage

回答2:

One of the way to keep track is whenever a book is downloaded store the required data in database and retrive it whenever required or delete it from database if no required in future.

Try this way.

回答3:

If your app has already downloaded books, then you need a ListView to display them. If, however, the problem is both in saving and listing, you should read the dev guide, esp about using File and getExternalFileDir.