title: How to call addEventListener to ScrollView in cocos2d-x 3.6?
body: <p>Could anyone give an example?
  I try the following code, it always shows up error "No viable conversion from xxxxx" on the line of addEventListener while compiling.</p>
  
  <pre><code>// create a scrollview and add event listener
  auto scrollView = cocos2d::ui::ScrollView::create();
  scrollView-&gt;addEventListener(CC_CALLBACK_2(GameMenuLayer::didScrollItemInfoPanel, this));
  
  ...
  
  // the callback function
  void GameMenuLayer::didScrollItemInfoPanel(Ref* ref, cocos2d::ui::ScrollviewEventType eventType) {
      cclog("did scroll...");
  }
  </code></pre>
  
  <p>I see the callback function definition is as the following, so how should I modify my code?</p>
  
  <pre><code>typedef std::function&lt;void(Ref*, EventType)&gt; ccScrollViewCallback;
  </code></pre>
  
  <p>I have tried the old method and it works fine, but it shows a warning message that old method is deprecated.</p>
  
  <pre><code>scrollView-&gt;addEventListenerScrollView(this, SEL_ScrollViewEvent(&amp;GameMenuLayer::didScrollItemInfoPanel));
  </code></pre>