How to implement onchildclick listener in this example?

Question

So i am having an expandable listview. What i want is to make clickable each children. if I press the first one I want to open the class1, if I press the second one I want to open the class2, if I press the third one I want to open the class3 and so on... I am new in programming so please explain me like you would do it for a dummie.

This is my Activity

public class Mecanica  extends ExpandableListActivity implements OnChildClickListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ExpandableListView expandbleLis = getExpandableListView();
        expandbleLis.setDividerHeight(2);
        expandbleLis.setGroupIndicator(null);
        expandbleLis.setClickable(true);

        setGroupData();
        setChildGroupData();

        NewAdapter mNewAdapter = new NewAdapter(groupItem, childItem);
        mNewAdapter.setInflater((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE), this);
        getExpandableListView().setAdapter(mNewAdapter);
        expandbleLis.setOnChildClickListener(this);
    }

    public void setGroupData() {
        groupItem.add("Directia");
        groupItem.add("Franarea");
        groupItem.add("Motorul");
        groupItem.add("Rotile");
        groupItem.add("Siguranta si control");
        groupItem.add("Suspensia");
        groupItem.add("Transmisia");
    }

    ArrayList<String> groupItem = new ArrayList<String>();
    ArrayList<Object> childItem = new ArrayList<Object>();

    public void setChildGroupData() {
        /**
         * Add Data For TecthNology
         */
        ArrayList<String> child = new ArrayList<String>();
        child.add("Java");
        child.add("Drupal");
        child.add(".Net Framework");
        child.add("PHP");
        childItem.add(child);

        /**
         * Add Data For Mobile
         */
        child = new ArrayList<String>();
        child.add("Android");
        child.add("Window Mobile");
        child.add("iPHone");
        child.add("Blackberry");
        childItem.add(child);
        /**
         * Add Data For Manufacture
         */
        child = new ArrayList<String>();
        child.add("HTC");
        child.add("Apple");
        child.add("Samsung");
        child.add("Nokia");
        childItem.add(child);
        /**
         * Add Data For Extras
         */
        child = new ArrayList<String>();
        child.add("Contact Us");
        child.add("About Us");
        child.add("Location");
        child.add("Root Cause");
        childItem.add(child);
    }    
}

And the adapter class

@SuppressWarnings("unchecked")
public class NewAdapter extends BaseExpandableListAdapter {

    public ArrayList<String> groupItem, tempChild;
    public ArrayList<Object> Childtem = new ArrayList<Object>();
    public LayoutInflater minflater;
    public Activity activity;

    public NewAdapter(ArrayList<String> grList, ArrayList<Object> childItem) {
        groupItem = grList;
        this.Childtem = childItem;
    }

    public void setInflater(LayoutInflater mInflater, Activity act) {
        this.minflater = mInflater;
        activity = act;
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return null;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return 0;
    }

    @Override
    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() {
            @Override
            public void onClick(View v) {
                Toast.makeText(activity, tempChild.get(childPosition),
                        Toast.LENGTH_SHORT).show();
            }
        });*/
        return convertView;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return ((ArrayList<String>) Childtem.get(groupPosition)).size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return null;
    }

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

    @Override
    public void onGroupCollapsed(int groupPosition) {
        super.onGroupCollapsed(groupPosition);
    }

    @Override
    public void onGroupExpanded(int groupPosition) {
        super.onGroupExpanded(groupPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        return 0;
    }

    @Override
    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;
    }

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

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

Answer 1

I can't find your OnChildClickListener, which you should implement.

This will give you access to the specific child clicked and hence the position in your List of items.

The implementation could look something like this example:

@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
    // Create a switch that switches on the specific child position.
    switch(childPosition) {
    case 0:
        // Go to child #0 specific class.
        Intent child0Intent = new Intent(this, Child0Activity.class);
        startActivity(child0Intent);
        break;
    case 1:
        // Go to child #1 specific class.
        Intent child1Intent = new Intent(this, Child1Activity.class);
        startActivity(child1Intent);
        break;
    }
    return false;
}

A full example of how to implement it can be found here:

http://www.mysamplecode.com/2012/10/android-expandablelistview-example.html