ListView with Custom NumberPickers - Incremented number not being displayed

Question

I am currently working on an Activity which requires a ListView with custom NumberPickers. I created the number picker as suggested here.

The problem which I am facing is quite frustrating; when I click on the + button of the number picker, the text view keeps displaying 0. I have tried all these suggestions but nothing has been changed.

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

    View vi = convertView;

    //ViewHolder holder = new ViewHolder();

    if(vi == null)
    {
        holder = new ViewHolder();

        vi = inflater.inflate(R.layout.materialdialogcontent, null);

        //Initialize Buttons and TextViews.

        holder.num.setText("0");

        holder.add.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v) 
            {
                counter++;
                holder.num.setText("" + counter);
            }
        });

        holder.sub.setOnClickListener(new View.OnClickListener()
        {   
            @Override
            public void onClick(View v) 
            {
                counter--;
                holder.num.setText("" + counter);
            }
        });


        //holder.pk = (NumberPicker)vi.findViewById(R.id.npMaterialAmount);

        vi.setTag(holder);
    }
    else
    {
    holder = (ViewHolder)vi.getTag();
    }

    holder.txt.setText(data.get(position).getName());
    //holder.pk.setMaxValue(20);
    //holder.pk.setMinValue(0);

    return vi;
}

public static class ViewHolder
{
    TextView txt;
    Button add;
    Button sub;
    TextView num;
    //NumberPicker pk;
}

The above code is found in my ListView Adapter.

The following is what I have already tried:

When I debug the above code, the counter increments, and the debugger variable shows that the TextView's text is actually being set to the number present in the counter, however the number displayed is still 0.

I have also tried setting an OnItemClickListener() to the ListView, and nothing happens still. I then removed the Button click listeners from the ListView Adapter class and placed them inside the ListView's onItemClickListener(). When debugging however, the Button click listeners are skipped by the debugger.

Do you have any other suggestions?

I would gratefully appreciate all help possible.

Updated:

holder.add.setTag(position);
    holder.add.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v) 
        {
            int position = (Integer)v.getTag();
            int temp = numPickerValues.get(position);
            temp += 1;
            numPickerValues.set(position, temp);
            notifyDataSetChanged();
        }
    });
    holder.num.setText(String.valueOf(numPickerValues.get(position)));
    return convertView;

Answer 1

Right now you're probably updating other views, also the counter variable use it's not ok. The right way of handling those row number pickers would be to save their current values in some data structure and set/update the current value from that list:

View vi = convertView;
ViewHolder holder;
if(vi == null) {
    holder = new ViewHolder();
    vi = inflater.inflate(R.layout.materialdialogcontent, null);
    //Initialize Buttons and TextViews.
    vi.setTag(holder);
} else {
    holder = (ViewHolder)vi.getTag();
}
holder.txt.setText(data.get(position).getName());
holder.add.setTag(position); // so we have the proper position in the onClick method
holder.add.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
       // there's no need for counter
      int position = v.getTag();
      // numberpickervalues is the array/list of int values representing the values from all the row
      // update the proper value  
      int temp = numPickerValues.get(position);
      temp += 1; // incremment the value
      numPickerValues.set(position, temp);
      notifyDataSetChanged(); // let the list know about this change
}
});
holder.num.setText(String.valueOf(numberPickerValues.get(position)));