ارتباط فرگمنت ها

public class HeadlinesFragmentextendsListFragment{
    OnHeadlineSelectedListener mCallback;

    // Container Activity must implement this interface
    publicinterfaceOnHeadlineSelectedListener{
        publicvoid onArticleSelected(int position);
    }

    @Override
    public void onAttach(Activity activity){
        super.onAttach(activity);
        
        // This makes sure that the container activity has implemented
        // the callback interface. If not, it throws an exception
        try{
            mCallback =(OnHeadlineSelectedListener) activity;
        }catch(ClassCastException e){
            thrownewClassCastException(activity.toString()
                    +" must implement OnHeadlineSelectedListener");
        }
    }
    
    ...
}

@Override
    public void onListItemClick(ListView l,View v,int position,long id){
        // Send the event to the host activity
        mCallback.onArticleSelected(position);
    }

public static class MainActivity extends Activity
        implementsHeadlinesFragment.OnHeadlineSelectedListener{
    ...
    
    publicvoid onArticleSelected(int position){
        // The user selected the headline of an article from the HeadlinesFragment
        // Do something here to display that article
    }
}

public static class MainActivity extends Activity
        implementsHeadlinesFragment.OnHeadlineSelectedListener{
    ...

    public void onArticleSelected(int position){
        // The user selected the headline of an article from the HeadlinesFragment
        // Do something here to display that article

        ArticleFragment articleFrag =(ArticleFragment)
                getSupportFragmentManager().findFragmentById(R.id.article_fragment);

        if(articleFrag !=null){
            // If article frag is available, we're in two-pane layout...

            // Call a method in the ArticleFragment to update its content
            articleFrag.updateArticleView(position);
        }else{
            // Otherwise, we're in the one-pane layout and must swap frags...

            // Create fragment and give it an argument for the selected article
            ArticleFragment newFragment =newArticleFragment();
            Bundle args =newBundle();
            args.putInt(ArticleFragment.ARG_POSITION, position);
            newFragment.setArguments(args);
        
            FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

            // Replace whatever is in the fragment_container view with this fragment,
            // and add the transaction to the back stack so the user can navigate back
            transaction.replace(R.id.fragment_container, newFragment);
            transaction.addToBackStack(null);

            // Commit the transaction
            transaction.commit();
        }
    }
}