Question

Im trying to add a list view to my activity. Here is what is suppose to happen:
The user clicks on a button and that uses an asyncTask to get data from the internet. That data should then be added to the list view. The data comes from a table online therefore it there are 10 rows in the table then there should be 10 values in the Listview.

1. But I’m having some problems.
   First of all can a listview be added to a pre-existing layout and be updated on the fly?

2. Does a list view mean you cannot use the setContentView() method and have to use setListAdapter?

3. If you have a layout that already has two buttons arranged on it can the list view be added in below them and still be implemented using the setContentView() method?

Thanks

Edit

Updated Code – Which works:

@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView( R.layout.new_sightings );

    ListView list = getListView();
    list.setAdapter( new ArrayAdapter<String>( this, android.R.layout.simple_list_item_1, values ) );
    list.setTextFilterEnabled( true );
}

XML Layout

?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation = "vertical">

  <TableLayout

android:layout_width = "fill_parent"
android:layout_height = "wrap_content"  
  >

  <TableRow

android:layout_width = "fill_parent"
android:layout_height = "wrap_content"
android:layout_weight = "1"
  >

  <TextView

android:id = "@+id/txtTitle"
android:layout_width = "wrap_content"
android:layout_height = "fill_parent"
android:layout_weight = "1"
android:gravity = "center"
android:text = "ISS Predictions" 
android:textStyle="bold"
android:textColor = "#FFFFFF"
    />

  <Button 
android:id="@+id/reloadTen" 
android:layout_height="wrap_content" 
android:layout_width ="fill_parent"
android:layout_gravity = "right"
android:layout_weight = "1"
android:text = "Reload"
android:textColor = "#FFFFFF"
android:textStyle = "bold"
android:background = "#000000"
/>

  </TableRow>

  </TableLayout>

   <ListView

android:id = "@+id/android:list"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:textSize = "15dp"
android:textStyle = "bold"

  />


</LinearLayout>

Answer 1

1) Yes, you can have a ListView in your layout, and update the data displayed by the ListView. Typically you’d make a class that inherits from ArrayAdapter to bridge the gap between your underlying data and generating views for your ListView.

When you want to update the data displayed, use add() and notifyDataSetChanged() on your adapter.

2) No. You call setListAdapter() only when your activity inherits from ListActivity and you have a ListView element with an id of @android:id/list. Here’s an example of such an element:

<ListView android:id="@android:id/list"
               android:layout_width="match_parent"
               android:layout_height="match_parent"
               android:layout_weight="1"/>

You still use setContentView() to pass in the desired XML layout to use.

3) Yes, for the reasons explained above.