Updating the list view when the adapter data changes

Question

When the data associated with array adapter is changed, invalidating the listview is sufficient to show the updated values? Following piece of code is not working, did i misunderstood something here.?

public class ZeroItemListActivity extends Activity {     private ArrayList<String> listItems=new ArrayList<String>();     private ListView mMyListView;     /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);         mMyListView=(ListView) findViewById(R.id.MyListView);         mMyListView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,listItems));     }     public void addItem(View v){         listItems.add("list Item");         mMyListView.invalidate();     } } 

Layout used :

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical" android:layout_width="fill_parent"     android:layout_height="fill_parent">     <TextView android:layout_width="fill_parent"         android:layout_height="wrap_content" android:text="@string/hello" />     <ListView android:layout_width="wrap_content"         android:layout_height="wrap_content" android:id="@+id/MyListView"></ListView>     <Button android:layout_width="wrap_content"         android:layout_height="wrap_content" android:id="@+id/AddItemsButton"         android:text="Add Items" android:onClick="addItem"></Button> </LinearLayout> 

Answer 1

substitute:

mMyListView.invalidate(); 

for:

((BaseAdapter) mMyListView.getAdapter()).notifyDataSetChanged();  

If that doesnt work, refer to this thread: Android List view refresh

Answer 2

Change this line:

mMyListView.setAdapter(new ArrayAdapter<String>(this,                             android.R.layout.simple_list_item_1,                             listItems)); 

to:

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,                                    android.R.layout.simple_list_item_1,                                     listItems) mMyListView.setAdapter(adapter); 

and after updating the value of a list item, call:

adapter.notifyDataSetChanged();