This is lab 6 in my ongoing series of jumpstart Android programming tutorials.
This lab will focus on selectable ListViews.
Here are some terms that you’ll need to understand to work with ListViews:
- Context
- Interface to information about an application environment
- Typically when a context parameter is needed for your app you will use (this)
- Adapters
- ArrayAdapter
- The ArrayAdapter constructor takes three parameters:
- The Context to use (this)
- The resource ID of a view to use
- The actual array or list of items to show
- By default, the ArrayAdapter will invoke toString() on the objects in the list and wrap each of those strings in the view designated by the supplied resource.
- android.R.layout.simple_list_item_1
- a built in resource that turns those strings into TextView objects styled in a particular way.
- Definitions for some built in resources can be found here
- The ArrayAdapter constructor takes three parameters:
- Listeners
- Interface to setup callbacks for actions on your widgets
- Use to set up link between a button and onClick
- ListView
- To use you will need to define one in your layout
- android.R.layout.simple_list_item_1
- android.R.layout.simple_list_item_single_choice
- android.R.layout.simple_list_item_multiple_choice
- Assign data to it using setAdapter()
- Assign functionality to catch users selections using a Listener using setOnItemClickListener()
- If your View is really just your list, you can make things easier on yourself by having your activity extend ListActivity
- It will then construct the full screen list for you
- You must name your ListView @android:id/list
- To use you will need to define one in your layout
Check out the two different ways of working with a ListView below. In this first example everything is setup in onCreate().
In this example everything we have broken it out.
Here are some different types of usage for a ListView.
It is quite versatile and can be used for single or multi selections.