How to Refresh Android List Adapter, so it shows new-added items

Question

I was working on a project. It\'s just showing a list of tasks and Adding new tasks to it. I have 3 CLASSES. One for adding, One for view and One to hold all information (or

Answer 1

You can use notifyDataSetChanged() method to update your listview.In your case you can use.

aa.notifyDataSetChanged();

Please Try this way....

public class MainActivity extends Activity {

ListView lView;
Button btnAdd;  

private ListView mainListView ;  
private ArrayAdapter listAdapter ;  


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

    mainListView = (ListView) findViewById( R.id.listView1 ); 
    btnAdd = (Button)findViewById(R.id.button1);

    // Create and populate a List of alphabet names.  
    String[] alphabets = new String[] { "A", "B", "C", "D",  
                                      "E", "F", "G", "H"};    
    ArrayList alphabetsList= new ArrayList();  
    alphabetsList.addAll( Arrays.asList(alphabets) );  

    // Create ArrayAdapter using the for the list.  
    listAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, alphabetsList);  


    // Set the ArrayAdapter as the ListView's adapter.  
    mainListView.setAdapter( listAdapter );      
    btnAdd.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

// Here I am adding more alphabets in the list on the listener of add button.
            listAdapter.add( "I" );  
            listAdapter.add( "J" );  
            listAdapter.add( "K" );  
            listAdapter.add( "L" );  
            listAdapter.add( "M" );  
        }
    });       
   }
 }