How To Manage The Fragments In Android Correctly?

I've met a lot of different code and each programmer makes its own way. I had a misunderstanding of one thing. it fragments. I met this code: public static final int FRAGMENT_M

Solution 1:

Your examples are all valid approaches (basically using the Android transactions to replace fragments). You are encapsulating the common actions into methods, which is always good OO.

Google shows a similar article here called 'building flexible ui's: http://developer.android.com/training/basics/fragments/fragment-ui.html

As for general patterns when using fragments, I try to think of a fragment as a 'section of a screens ui' that may be reused and or can be logically grouped.

When deciding how you organise your fragments when associating activities, there are two that I know of (I have attended many presentations at Droidcon and these are always described):

1. Create a FragmentActivity for each logical screen in the UI, then make it manage the one or more fragments that are using on that screen.
2. Create one single activity for the entire app which then manages every fragment.

Both are valid, but I usually go with option 1, creating a activity per UI screen and then having that activity manage the fragments used on that screen. It grows better and seems more OO to me.

I only rarely use option 2 if the app is very very compact and small (not many ui screens). As it gets messy fast.

Then as more UI screens are created, I create another activity for it, finally adding that screens fragments.

Although you didn't specifically ask about communication between fragments, I also find that my code is a lot easier to maintain by using one of the Android Event Bus libraries (Green robot event bus is my favourite ,but I hear good things about 'otto' too).

By using an event bus, you can easily communicate between fragments/screens by firing an event.