title: Android setOnCheckedChangeListener calls again when old view comes back
body: <p>I cannot solve an issue with the getGroupView-method. </p>
  
  <p>the problem is that the listener setOnCheckedChangeListener is getting invoked to many times. </p>
  
  <p>Let say i check a certain checkbox-item. Then I scroll it out of view and then scroll back. What happends is that the listener is called once again. And the problem is that I store checkbox-id's in an arraylist inside this listener to use it later in the code. The consequence is that more elements is added to the arraylist everytime the listener is called and distortes the data.  </p>
  
  <p>Is there a solution to this? what should I do? Should I for instance unregister the listener?</p>
  
  <pre><code>@Override
   public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
       View view = null;
  
       final int group_position = groupPosition;
       if (convertView == null) {
           LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
           view = inflater.inflate(R.layout.activity_phrase, parent, false);
           final ViewHolder viewHolder = new ViewHolder();
           viewHolder.text = (TextView) view.findViewById(R.id.groupTitle);
           viewHolder.checkBox = (CheckBox) view.findViewById(R.id.check);
           viewHolder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
  
              @Override
              public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                  // TODO Auto-generated method stub
  
                  if (buttonView.isChecked()) {
                      checked.add((Integer) viewHolder.checkBox.getTag());
                  }
                  else {
                      checked.remove((Integer) viewHolder.checkBox.getTag());
                  }
  
              }
          });
  
          view.setTag(viewHolder);
          viewHolder.checkBox.setTag(groupPosition);
  
       } else {
           view = convertView;
           ((ViewHolder)view.getTag()).checkBox.setTag(groupPosition);
       }
  
       ViewHolder holder = (ViewHolder) view.getTag();
       holder.text.setText(titles[groupPosition]);
  
       for (int i = 0; i &lt; checked.size(); i++) {
           if (checked.get(i) == group_position) {
               holder.checkBox.setChecked(true);
           }
           else if (checked.get(i) != group_position) {
               holder.checkBox.setChecked(false);
           }
       }
  
       return view;
   }
  </code></pre>