It's all about ListViews

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     One of the most frequent components used in an android application is a ListView, it's basically a UI component which displays a list of items (simple String items or richer items), with an adapter which can be bound to a ListView and a collection of some sort.

What do we need in order to create a ListView?
Two main options:

1. within the context of an Activity which extends the Activity Class
2. Within the context of an Activity which extends ListActivity (that being said if the whole activity is a 
    list)

We’ll look at the first option
1. Create an Activity, and a matching Xml layout file.
    In the layout file, add a ListView control using <ListView></ListView>, don't forget to give it   
    layout_width,layout_height,id.
    for example:
    <ListView
          android:id="@+id/your_listview_id"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content">
    </ListView>
2. In the Activity, get A reference to the ListView by:
    ListView myListView = (ListView)findViewById(R.id.your_listview_id);
3. Create the actual data that should be populated in the ListView
     for example : 
      String[] names = {"John","Benny","Sharon","Sharona","Simona","Bill"};
      (perhaps a more comfortable way is to create a <string-array> in the resource file under 
      res/values/string.xml).
4. Ok, so far we have an Empty ListView and a collection of data stored in a String Array, we 
    need to be      
    able to bind that data to the listView, for this we will need an adapter:
    ArrayAdapter<String> adapter  =  
                     new ArrayAdapter<String>
                     (this,android.R.layout.simple_list_item_1,names); 

    let's see what are the components:
    1. this - the context
    2. android.R.layout.simple_list_item_1 - this is an id for a single layout of an item in the 
        list (taken by reference directly from the resources of the android SDK, we can see this by 
        the syntax "android.R.layout.simple_list_item_1).
    3. name -  the string array which we've defined.
    
5. finally, we connect the ListView to the adapter by using:
    myListView.setAdapter(adapter);

On the next post, we'll see how we create rich ListView's where each item on the list contains various controls.

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