在Android中将数据从一个片段传递到下一个片段

Question

In one of my project I am using 2 fragments.One fragment is displaying a list of items.So I want when the topic will be selected in first fragment the details should be changed in another fragment.Data I am able to pass from one fragment to other but the view is not changing.In which method I should implement the view of second fragment so that it can change accordingly. Please give me good tutorial or example for these.

Here I have to develop one android example, I have to run the app means displayed category name well on horizontal listview of my first fragment.I have to click any category means how can I pass the category name on 2nd fragment.Please give me solution for this problem.

I have used below code:

public class Home extends FragmentActivity{

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}

1st fragment code:

public class MainActivity extends Fragment {
static final String URL = "http://dev2.mercuryminds.com/webservices/new_feed_articls.xml";

 static String KEY_CATEGORY = "Categories";

 static final String KEY_TITLE = "Category";
 LazyAdapter adapter;

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
     View view = inflater.inflate(R.layout.activity_main,
                container, false); 


    final ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
    XMLParser parser = new XMLParser();
        String xml = parser.getXmlFromUrl(URL); // getting XML from URL
        Document doc = parser.getDomElement(xml); // getting DOM element

        NodeList nl = doc.getElementsByTagName(KEY_TITLE);


        // looping through all song nodes &lt;song&gt;
        for (int i = 0; i < nl.getLength(); i++) {
            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>   ();
            Element e = (Element) nl.item(i);
            map.put( KEY_TITLE,((Element)nl.item(i)).getAttribute("name"));

           // map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
            songsList.add(map);
        }
        HorizontalListView list = (HorizontalListView) view.findViewById(R.id.listView1);
    adapter = new LazyAdapter(getActivity(), songsList);
      list.setAdapter(adapter);

       list.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            HashMap<String, String> map = songsList.get(position);
            Intent in = new Intent();
            in.setClass(getActivity(), SubCate.class);
           // in.putExtra(KEY_TITLE, map.get(KEY_TITLE));

                     startActivity(in); 
        }  

     });
        return view;
    }}

How can i display category name on 2nd Activity...pls give me code for these...

EDIT:

Hi i have changed code like on my first activity:

   HashMap<String, String> map = songsList.get(position);
            SubCate frag = (SubCate) getFragmentManager().findFragmentById(R.id.frag_2);
            if (frag != null && frag.isInLayout()) {
            frag.setText(getCapt(map));
            }
            }
            private String getCapt(HashMap<String, String> map) {
            if (map.containsValue("notchbolly")) {
            return "dadad";
            }
                return "veeman"; 

on next activity:

public void setText(String item) {
 TextView view = (TextView) getView().findViewById(R.id.cate);
 view.setText(item);
  }

its woked well while directly mention the name on if (map.containsValue("notchbolly")).but i have to display the name without mention name directly.if i have to click any category means that category name is displayed on next fragment.how can i do ?????

Answer 1

Using interface method we can transfer data between fragment to fragment

In fragmentA create interface and sent data to this interface and implement this interface method in fragmentB and get required data

the following code is useful for u

Code in FragmentA:

    public class FragmentA extends Fragment  {

    // interface method
    public    InterfaceDataCommunicatorBetweenfragmentAToFragmentB     iInterfaceDataCommunicatorBetweenfragmentAToFragmentB;

    // Data to send
    String mDataString;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        // use this line where u send data  
        iInterfaceDataCommunicatorBetweenfragmentAToFragmentB.upDatedData(mDataString);

        View view = inflater.inflate(R.layout.sent_box, container, false);


        return view ;
    }

    /**
         * Interface method to send data to fragmentB
         * 
         */
        public interface InterfaceDataCommunicatorBetweenfragmentAToFragmentB                                       {
            public void upDatedData(String data);

        }
    }

Code in FragmentB:

   class FragmentB extends Fragment implements InterfaceDataCommunicatorBetweenfragmentAToFragmentB {

    // interface method
    public InterfaceDataCommunicatorBetweenfragmentAToFragmentB iInterfaceDataCommunicatorBetweenfragmentAToFragmentB;

    // fragmentA data
    String mgetUpdatedData


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {


            View view = inflater.inflate(R.layout.get_box, container, false);


        return view ;
    }

   /**
     * Interface method coming from fragment a to fragmentB after  implement interface in fragmentB
     */
    public void upDatedData(String data) {
        this.mgetUpdatedData = data;
    }

    @Override
    public void onAttach(Activity activity) {
        // TODO Auto-generated method stub
        super.onAttach(activity);
        try {
            iInterfaceDataCommunicatorBetweenfragmentAToFragmentB = (InterfaceDataCommunicatorBetweenfragmentAToFragmentB ) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement interface");
        }

    }

Answer 2

You need to implement interface mechanism.

Refer following links for further details.

http://developer.android.com/guide/components/fragments.html#CommunicatingWithActivity http://developer.android.com/training/basics/fragments/communicating.html