How do I create an expandable list view in android from a List of Objects?

Question

I have a list of objects in android. I want to iterate through the list and create an expandable list view, with one entry per object. I already have the ExpandableListView created in the xml file. So i Know I start with:

ExpandableListView results = ((ExpandableListView)rootView.findViewById(R.id.results));

I want to go through the list of Objects and create a Parent for each object, and each Child will be an instance variable of the main Object.

for instance:

Parent = Object.Title
  Child1 = Object.Taste
  Child2 = Object.smell
Parent1 = Object1.Title
  Child1 = Object1.Taste
  Child2 = Object1.smell

Answer 1

you need to create adapter which extends BaseExpandableListAdapter it will manage child view and parent view . see this for details.

Answer 2

You have to basically extend your adapter with BaseExpandableListAdapter and override methods of it.

here is a good example

http://theopentutorials.com/tutorials/android/listview/android-expandable-list-view-example/

Answer 3

Extend your custom Adapter with BaseExpandableListAdapter and ovverride getChildView(...) and getGroupView(...) like this:

public View getChildView(int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
          tempChild = (ArrayList<String>) Childtem.get(groupPosition);
          TextView text = null;
          if (convertView == null) {
                 convertView = minflater.inflate(R.layout.childrow, null);
          }
          text = (TextView) convertView.findViewById(R.id.textView1);
          text.setText(tempChild.get(childPosition));
          convertView.setOnClickListener(new OnClickListener() {
                 public void onClick(View v) {
                       Toast.makeText(activity, tempChild.get(childPosition), Toast.LENGTH_SHORT).show();
                 }
          });
          return convertView;
   }

public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
          if (convertView == null) {
                 convertView = minflater.inflate(R.layout.grouprow, null);
          }
          ((CheckedTextView) convertView).setText(groupItem.get(groupPosition));
          ((CheckedTextView) convertView).setChecked(isExpanded);
          return convertView;
   }

See complete sample source code here