Fragment Guide

FragmentGuide.txt

Add Fragment through XML.
  1. Create a xml for the fragment.
  2. Create a class for the fragment and extend android.app.Fragment(for Honeycomb/API 11 and above).
  3. Link fragment class with the xml created in step 1. Link them inside onCreateView method.
     return inflater.inflate(R.layout.fragment_xml_name, container, false);
     
  4. Add fragment to activity through xml file. Open activity's xml.
     <fragment
        android:id="@+id/fragment_xml_a"
        class="FragmentXMLA" />
        
Introduction to Fragment Manager and Fragment Transactions
  1. Fragment Manager
     - Maintains list of Fragments in the current Activity.
     - Track Fragment Using ID (Assign an id to a fragment, Use findFragmentById with Fragment Manager to get that fragment).
     - Track Fragment Using TAG (Assign a TAG to a fragment, Use findFragmentByTag with Fragment Manager to get that fragment).
  
  2. Fragment Transactions
     - add - Add a fragment to the activity.
     - remove - Remove an existing fragment, its view is also removed.
     - replace - Remove one fragment from the activity and add another.
     - hide - Hides an existing fragment, its view is hidden.
     - show - Show previously hidden fragment.
  
Add Fragment through code.
  1. Make an Activity.
  2. Create a layout file for the Fragment in XML.
  3. Create a class in Java that extends from Fragment or its subsclasses.
  4. Link the layout of the Fragment with its Java file.
  5. Create an object of your Fragment class in your Activity.
  6. Get a reference to FragmentManager using getFragmentManager() or getSupportFragmentManager().
  7. FragmentManager is reponsible for interacting with Fragments, ex: finding them.
  8. Use the FragmentManager to begin a FragmentTransaction.
  9. FragmentTransaction involves operations such as add, remove, replace, hide etc.
  10. For example use the FragmentTransaction to Add the fragment object.
  11. Commit or finish the FragmentTransaction.