How to dynamically update a ListView with custom adapter?

How to dynamically update a ListView with custom adapter?

I have a main activity that creates a ListView and a custom adapter. I'm
able to populate the ListView if I have the List already created
beforehand, but how do I populate it with dynamically fetched data?
Existing code: MainActivity
public class MainActivity extends Activity {
private ListView myListView;
private Context ctx;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.MainActivity);
ctx = this;
List<Items> myList = new ArrayList<Items>();
myList.add(new Item("Name 1", "Desc 1"));
myList.add(new Item("Name 2", "Desc 2"));
myList.add(new Item("Name 3", "Desc 3"));
myList.add(new Item("Name 4", "Desc 4"));
myList.add(new Item("Name 5", "Desc 5"));
myListView = (ListView)findViewById(R.id.list);
MyListAdapter myAdapter = new MyListAdapter(ctx,R.layout.listitem,
myList);
myListView.setAdapter(myAdapter);
}
}
MyListAdapter
public class MyListAdapter extends ArrayAdapter<Items> {
private int resource;
private LayoutInflater mLayoutInflater;
public MyListAdapter ( Context ctx, int resourceId, List<Items> objects) {
super( ctx, resourceId, objects );
resource = resourceId;
mLayoutInflater = LayoutInflater.from( ctx );
}
@Override
public View getView ( int position, View convertView, ViewGroup parent ) {
// create a new view of my layout and inflate it in the row
convertView = ( RelativeLayout ) mLayoutInflater.inflate( resource,
null );
// Extract the item object to show
Items item = (Items) getItem( position );
// Take the TextView from layout and set the item name
TextView txtName = (TextView) convertView.findViewById(R.id.listName);
txtName.setText(item.getName());
/* Take the TextView from layout and set the item description */
TextView txtDesc = (TextView)
convertView.findViewById(R.id.listDescription);
txtDesc.setText(item.getDesc());
return convertView;
}
}
Item
public class Item {
private String name;
private String desc;
public Item(String name, String desc) {
super();
this.name = name;
this.desc = desc;
}
public String getName() {
return name;
}
public void setName(String nameText) {
name = nameText;
}
public String getDesc() {
return desc;
}
public void setDesc(String descText) {
desc= descText;
}
}
How can I modify my code such that a function in the background retrieves
the items to the custom adapter and populates the ListView? I tried using
an AsyncTask but couldn't manage to get it to work.
Thanks.
Edit: Added the following AsyncTask in MainActivity after onCreate() just
to test things out. It's working in that I can see the counting from 1 to
5 and then done. How do I get the AsyncTask to update my adapter and
ListView though? What should onCreate() pass to the AsyncTask and what
should AsyncTask return?
private class GetItems extends AsyncTask<Void, Integer, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
TextView myMsg = (TextView)findViewById(R.id.topMsg);
myMsg.setText("Loading...");
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
TextView myMsg = (TextView)findViewById(R.id.topMsg);
for (int i=1;i<=5;i++) {
try {
Thread.sleep(1000);
publishProgress(i);
} catch (InterruptedException e) {
}
}
return null;
}
protected void onProgressUpdate(Integer... values) {
TextView myMsg = (TextView)findViewById(R.id.topMsg);
myMsg.setText(Integer.toString(values[0].intValue()));
}
@Override
protected void onPostExecute(Void result) {
TextView myMsg = (TextView)findViewById(R.id.topMsg);
myMsg.setText("Done!");
}
}