ExpandableListView with icon

This example display icon in ExpandableListView.

ExpandableListView with icon

Modify /res/layout/group_layout.xml to add a TextView to display our icon.

<?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="wrap_content"
    android:background="#000000"
    android:orientation="horizontal"
    android:padding="8dp" >

    <ImageView
        android:id="@+id/groupimage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
        
        
    <TextView
        android:id="@+id/group"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textStyle="bold" />

</LinearLayout>

Modify getGroupView() in MyBaseExpandableListAdapter.java to set ImageView.

package com.example.androidexpandablelistview;

import java.util.HashMap;
import java.util.List;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MyBaseExpandableListAdapter extends BaseExpandableListAdapter {
 
 private Context context;
    private List<String> listGroup;
    private HashMap<String, List<String>> listChild;

 public MyBaseExpandableListAdapter(Context c, List<String> lg,
            HashMap<String, List<String>> lc) {
  context = c;
  listGroup = lg;
  listChild = lc;
 }

 @Override
 public Object getChild(int groupPosition, int childPosition) {
  return listChild.get(listGroup.get(groupPosition)).get(childPosition);
 }

 @Override
 public long getChildId(int groupPosition, int childPosition) {
  return childPosition;
 }

 @Override
 public View getChildView(int groupPosition, int childPosition, 
   boolean isLastChild, View convertView, ViewGroup parent) {
  
        if (convertView == null) {
            LayoutInflater infalInflater = 
              (LayoutInflater)context
              .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.item_layout, null);
        }
 
        TextView textViewItem = 
          (TextView)convertView.findViewById(R.id.item);
        
        String text = (String)getChild(groupPosition, childPosition);
 
        textViewItem.setText(text);
        return convertView;
 }

 @Override
 public int getChildrenCount(int groupPosition) {
  return listChild.get(listGroup.get(groupPosition)).size();
 }

 @Override
 public Object getGroup(int groupPosition) {
  return listGroup.get(groupPosition);
 }

 @Override
 public int getGroupCount() {
  return listGroup.size();
 }

 @Override
 public long getGroupId(int groupPosition) {
  return groupPosition;
 }

 @Override
 public View getGroupView(int groupPosition, 
   boolean isExpanded, View convertView, 
   ViewGroup parent) {
  
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater)context
              .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.group_layout, null);
        }
        
        String textGroup = (String)getGroup(groupPosition);

        //get application resource/drawable not in Activity class, using context
        Resources contextResources = context.getResources();
        Drawable groupDrawable = contextResources.getDrawable(R.drawable.ic_launcher);
        //Set ImageView
        ImageView groupImage = (ImageView)convertView.findViewById(R.id.groupimage);
        groupImage.setImageDrawable(groupDrawable);
 
        TextView textViewGroup = (TextView)convertView.findViewById(R.id.group);
        textViewGroup.setText(textGroup);
 
        return convertView;
 }

 @Override
 public boolean hasStableIds() {
  return false;
 }

 @Override
 public boolean isChildSelectable(int groupPosition, int childPosition) {
  return true;
 }

}

Remark: Alternatively, you can set android:src in XML directly.

- For MainActivity.java and activity_main.xml, refer to last post "Detect user action on ExpandableListView, with various Listeners".
- For item_layout.xml, refer to the post "ExpandableListView example".