title: How to change the drawable of radio button to custom icon and recover?
body: <p>I met the problem when I try to use radio button in RecyclerView. It`s easy to change the drawable to a custom one. But as we know that the view in the RecycerView is recycled, if I changed the drawable to a custom one, when it is used again it should show as the default drawable. Since the radio button must be selectable again. So, if I want to accomplish this function, any good idea?</p>
  
  <p>Here is the explanation:</p>
  
  <pre><code>private List&lt;MotocareService&gt; purchased = new LinkedList&lt;&gt;();
  
  @Override
  public void onBindViewHolder(K holder, int position) {
      if (purchased.contains(item)) {   // line 5
          currentRadio.setButtonDrawable(R.drawable.ic_check_black);   // line 6
          currentRadio.setEnabled(false);
      } else {
          // line 9: need to change the drawable back
          currentRadio.setEnabled(true);
      }
  }
  </code></pre>
  
  <p>As shown above, at line 5, I want to judge whether MotocareService item is in the purchased list. If it is in the list, I have to change its drawable to R.drawable.ic_check_black and disable it. But since the view is recycled and it will be used again in another position. I have to handle another case -- the item not in the list. Also, the item must be selectable and enabled, so that the user can select the item. </p>