CODEWITHSUNDEEP
androidjsonlistview
Jerry A
Jerry A

Reputation: 21

Refresh listview after click Android

I have an Android app (created from tutorials) that creates a list from JSON and depending on the data it creates a yellow or black background.

What i want is when a person clicks on a item from the list, data is transmitted to a server (works) But then i want to refresh my list because the data has changed (cannot get this to work) Can anyone help me?

This is my code:

public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://www.somesite.com/kaku/kaku_list.php/";

// JSON Node names
private static final String TAG_ONTVANGERS = "ontvangers";
private static final String TAG_ID = "id";
private static final String TAG_BESCHRIJVING = "beschrijving";
private static final String TAG_KANAAL = "kanaal";
private static final String TAG_NUMMER = "nummer";
private static final String TAG_STATUS = "status";

// contacts JSONArray
JSONArray ontvangers = null;

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

    // Hashmap for ListView
    ArrayList<HashMap<String, String>> ontvanger = new ArrayList<HashMap<String, String>>();

    // Creating JSON Parser instance
    JSONParser jParser = new JSONParser();

    // getting JSON string from URL
    JSONObject json = jParser.getJSONFromUrl(url);

    try {
        // Getting Array of Contacts
        ontvangers = json.getJSONArray(TAG_ONTVANGERS);

        // looping through All Contacts
        for(int i = 0; i < ontvangers.length(); i++){
            JSONObject c = ontvangers.getJSONObject(i);

            // Storing each json item in variable
            String id = c.getString(TAG_ID);
            String beschrijving = c.getString(TAG_BESCHRIJVING);
            String kanaal = c.getString(TAG_KANAAL);
            String nummer = c.getString(TAG_NUMMER);
            String status = c.getString(TAG_STATUS);

            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            // adding each child node to HashMap key => value
            map.put(TAG_ID, id);
            map.put(TAG_BESCHRIJVING, beschrijving);
            map.put(TAG_KANAAL, kanaal);
            map.put(TAG_NUMMER, nummer);
            map.put(TAG_STATUS, status);


            // adding HashList to ArrayList
            ontvanger.add(map);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }


    /**
     * Updating parsed JSON data into ListView
     * */
    ListAdapter adapter = new OntvangerAdapter(this, ontvanger,
            R.layout.list_item,
            new String[] {  TAG_BESCHRIJVING, TAG_ID, TAG_STATUS }, new int[] {
            R.id.beschrijving, R.id.Ontvanger_id, R.id.status});


    setListAdapter(adapter);
    // selecting single ListView item
    ListView lv = getListView();

    // Launching new screen on Selecting Single ListItem
    lv.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
                            // getting values from selected ListItem
            String Ontvanger_id = ((TextView) view.findViewById(R.id.Ontvanger_id)).getText().toString();
            JSONParser jParser = new JSONParser();
            String url1 = "http://www.somesite.com/kaku/action.php?id="+Ontvanger_id+"/" ;
            // getting JSON string from URL
            jParser.getJSONFromUrl(url1);



        }



    });


}

}

Upvotes: 0

Views: 938

Answers (3)

Raghunandan
Raghunandan

Reputation: 133560

From your comments

ListAdapter does not have notifyDataSetChanged()

http://developer.android.com/reference/android/widget/ListAdapter.html

You will to use ArrayAdapter or BaseAdapter. Its better to use a Custom Listview with a Custom Adapter extending either ArrayAdapter of BaseAdapter.(you can customize listview items easily).

http://developer.android.com/reference/android/widget/ArrayAdapter.html

http://developer.android.com/reference/android/widget/BaseAdapter.html#notifyDataSetChanged()

public void notifyDataSetChanged ()

Added in API level 1

Notifies the attached observers that the underlying data has been changed and any View reflecting the data set should refresh itself.

Upvotes: 1

Riandy
Riandy

Reputation: 372

To update the data/list in list view, you have to make a call to the method notifyDataSetChanged();

How and when to call that? After you modify your ontvanger , call the function above. Another side note, I think for newer API, you are not allowed to make HTTP request on UI thread anymore, you have to do it on AsyncTask or some background thread.

Hope that helps

Upvotes: 0

marshallino16
marshallino16

Reputation: 2671

Use the method notifyDataSetCHanged(); and it'll be good.

Upvotes: 0

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