Android List View sample

List View  :  As the name suggests it displays items in a list.  The user gets a list of items (a scrollable one when the number of items are not sufficient in the screen )  and when clicked on any item in the list view displays details about the clicked item.

By default the list items are textViews.

If you observe a list view can be seen in Contacts list , messages , songs list etc in a mobile .

A listView can be implemented in Android in two ways.

1. Using  ListActivity .
2. Using  ListView in XML file .

Using listActivity

In this we dont write anything in the xml file except the layout. 

My sample xml file looks like this :

   

android:layout_width="fill_parent" 

android:layout_height="fill_parent" 

 android:orientation="vertical">

 

Here i am just setting the layout as a linear layout and giving the properties.

And the Activity File looks like this :

1.  public class ListExampleActivity extends ListActivity implements
2. OnItemClickListener {
3. /** Called when the activity is first created. */
4. 
   
5. ArrayAdapter aa;
6. ListView lv;
7. String[] months = { "January", "February", "March", "April", "May", "June", "July" ,"August"       ,"September", "October",  "November" ,"December"};
8. 
   
9. @Override
10. public void onCreate(Bundle savedInstanceState) {
11. super.onCreate(savedInstanceState);
12. 
    
13. aa = new ArrayAdapter(this,
14. android.R.layout.simple_list_item_1, months);
15. setListAdapter(aa);
16. 
    
17. lv = getListView();
18. lv.setOnItemClickListener(this);
19. 
    
20. }
21. 
    
22. public void onItemClick(AdapterView arg0, View arg1, int arg2, long arg3) {
23. // TODO Auto-generated method stub
24. Toast.makeText(this,
25. "Item is clicked " + ((TextView) arg1).getText() + "  " + arg2,
26. 600).show();
28. }
29. }

Adapters are used in order to bind data with views.

In the similar way i am binding the data (the string array ) with the view (list view) using adapters.

Check the line 1 : we are using a ListActivity. 

       line 13 :  creates a arrayadapter with the data binded to it as the last parameter(months)

       line 17  : getting the default list view .

    line 18  : Setting the click event for the list item. (This will invoke the onItemClick())

    line 23  :   Displays the item that is clicked.

There is no need to change the manifest file for this task.

You can also use XML file to get a list layout.

The output will look something like this