Fragments allow modularizing an app's UI into reusable components. A fragment represents a portion of UI within an activity and has its own lifecycle. Multiple fragments can be used within a single activity to create a multi-pane UI or reuse fragments across activities. Key advantages are modularity, ability to reuse fragments, and maintaining a back stack of fragment states. The document discusses implementing fragments in different screen types, writing fragment and activity classes, and including fragments in layouts. It also covers fragment types like ListFragment and DialogFragment and ensuring compatibility by adding the support library.

1. An Introduction To
Fragments In Android
By: Ritesh Bhattarai
(reetesh.com.np)
Date: 13th October, 2012

2. What is a fragment?
A fragment is, as the name suggests, a chunk
of user interface with its own lifecycle which
must exist within an activity.
Multiple fragments can be used in a single
activity to form a multi-pane UI or reuse a
fragment in multiple activities.

3. Advantages of fragments
• It can modularize a single activity into
smaller units of UI, making it more flexible
and easier to manage.
• A fragment can exist without a UI screen
and act as an invisible worker for the activity.
• A fragment can be reused with multiple
activities.
• A fragment lets us maintain a "back-stack" of
its state.

4. Implementation in different screens

5. Implementations in paged layouts

6. Writing Fragment Layout
A fragment layout is similar to an activity layout.

7. Writing A Basic Fragment Class

8. Including Fragment Into Main Layout

9. Writing Main Activity Class

10. Fragment Types
ListFragment
DialogFragment
Custom Fragment (e.g Grid)

11. Compatibility
You can download the compatibility package using the Android
SDK Manager as shown below.

12. Compatibility (contd.)
To use the compatibility package, you must add
it to your project and include in the build path.
This can be done by Right clicking your Android
project-> Selecting Android Tools-> Add
compatibility Library.

13. Resources
API Guide
http://developer.android.com/guide/components/fragments.html
Tutorials
https://github.com/posco2k8/fragment_basic_tutorial
https://github.com/posco2k8/fragment_tabs_tutorial
Examples
https://github.com/jrgleason/android-fragments-example

14. Thank You