Android ExpandableListView.


Android ExpandableListView Tutorial and Examples.

An ExpandableListView is a view that shows items in a vertically scrolling two-level list. You can imagine it's a form of a ListView given the name or the fact that it derives from it, however ExpandableListView is obviously more complex in that it's view items can be expanded and collapsed.

It allows two levels:

  1. groups which can individually be expanded
  2. children shown when the groups are expanded.

Powering ExpandableListView is the ExpandableListAdapter. It is this adapter that supplies items to populate our ExpandableListView.

ExpandableListView API Definition.

ExpandableListView isn't young, even if alot of developers haven't used it yet. It has existed since the beginning of android, API level 1.

As a class it derives from [ListView](/android/listview:

public class ExpandableListView extends ListView 

Both reside in the android.widget package.

Here's ExpandableListView's inheritance hierarchy:

java.lang.Object
   ↳    android.view.View
       ↳    android.view.ViewGroup
           ↳    android.widget.AdapterView<android.widget.ListAdapter>
               ↳    android.widget.AbsListView
                   ↳    android.widget.ListView
                       ↳    android.widget.ExpandableListView

States and Indicators

Beside the item views in your ExpandableListView normally you see an indicator. This visually notifies you that you need to either expand to see more content or close the child. They tell you the current state of the expandable listview.

These states can be:

  1. Expanded group.
  2. Collapsed group
  3. Child
  4. Last child).

These indicators can be set using the setChildIndicator(Drawable) or setGroupIndicator(Drawable) (or the corresponding XML attributes).

The default style for an ExpandableListView provides indicators which will be shown next to Views given to the ExpandableListView.

The layouts android.R.layout.simple_expandable_list_item_1 and android.R.layout.simple_expandable_list_item_2 (which should be used with SimpleCursorTreeAdapter) contain the preferred position information for indicators.

You can find more documentation about ExpandableListView here.

Top Android ExpandableListView Examples

Let's look at some examples.

Android ExpandableListView tutorial with images and text tutorial.

Everyone knows and loves android listviews.However, listviews have a more powerful sister known as ExpandableListeView. These are views that show items in a vertically scrolling two-level list.

This is powerful when you want to group items in a list. The items groups can be expanded to show their children, which are also lists themselves. ExpandableListViews should not be confused with accordions.

They are lists inside list items. ExpandableListView items come from ExpandableListAdapter. ExpandableListViews do derive from ListViews, hence having the flexibility and capability of Listviews themselves.

They are simply ListViews nested inside ListView Items. They were added to android in API Level 1, so have actually been around for along time even though most people are obsessed with ListViews and RecyclerViews.

Best regards..

How do You Feel after reading this?

According to scientists, we humans have 8 primary innate emotions: joy, acceptance, fear, surprise, sadness, disgust, anger, and anticipation. Feel free to tell us how you feel about this article using these emotes or via the comment section. This feedback helps us gauge our progress.

Help me Grow.

I set myself some growth ambitions I desire to achieve by this year's end regarding this website and my youtube channel. Am halfway. Help me reach them by:




Recommendations


What do You Think


Previous Post Next Post