Question

I have a ListView with a Custom Adapter, and I need to access the View of individual rows of this ListView. I am trying to do it using getChildAt(), but it is returning null.

Here’s my ListView:

myListView = (ListView) findViewById (R.id.listViewLayout);

This is the custom adapter:

    public class MyListAdapter extends BaseAdapter {
       ...
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            if (convertView == null) {
                LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = inflater.inflate(R.layout.list_row_layout, parent, false);
            }
            ...
    }

I create a List, and set it for the ListView:

List <String> myList = new ArrayList<String>();
myList.add("entry 1");
myList.add("entry 2");
myList.add("entry 3");
MyListAdapter myListAdapter = new MyListAdapter(getApplicationContext(), myList);
myListView.setAdapter(myListAdapter);

Now, I want to access the View for individual rows.

View v = myListView.getChildAt(myListView.getFirstVisiblePosition());

This v is null, no matter what. Additionally, myListView.getChildCount() always returns null.

What am I missing? Do I need to add the convertView to parent in getView()? Am I passing wrong parameters to inflate?

I have struggled a lot to figure this out. Please help me!

EDIT: I am posting the MyListAdapter class:

public class MyListAdapter extends BaseAdapter {

    private Context context;
    private List<String> myList;

    public MyListAdapter(Context c, List<String> m) {
        context = c;
        myList = m;
    }

    @Override
    public int getCount() {
        return myList.size();
    }

    @Override
    public Object getItem(int position) {
        return myList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        final int pos = position;

        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.list_row_layout, parent, false);
        }

            TextView text = (TextView) convertView.findViewById(R.id.itemText);
            text.setText(myList.get(pos));

            // Set the onClick Listener on this button
            Button rowButton = (Button) convertView.findViewById(R.id.itemButton);

            //commenting next two lines makes the list row clickable
            rowButton.setFocusableInTouchMode(false);
            rowButton.setFocusable(false);

            rowButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    Toast.makeText(context, myList.get(pos), Toast.LENGTH_SHORT).show();
                } 
            });  
            convertView.setTag(pos);
            return convertView;
    }
}

Answer 1

In all probability you’re doing all of this in onCreate(). Any view-related methods will return null (or empty) because the list has not been rendered yet. What do you need the child view for?