Flex 4 Scroller

Question

在我的應用程序中，我使用了一個Scroller組件。爲了知道內容何時滾動，我似乎無法弄清楚應該在哪個事件中設置偵聽器。我在Scroller.verticalScrollBar屬性上嘗試Event.CHANGE屬性，但顯然，當用戶使用鼠標滾輪或箭頭鍵滾動時，該事件不會觸發。

Answer 1

您可以在Scroller的視口上偵聽propertyChange事件。下面是演示如何這可能完成的應用程序：

<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
       xmlns:s="library://ns.adobe.com/flex/spark" 
       creationComplete="init()"> 
    <fx:Script> 
     <![CDATA[ 
      import mx.events.PropertyChangeEvent; 

      private function init():void { 
       // spark Scroller: listen on the viewport property 
       myScroller.viewport.addEventListener(PropertyChangeEvent.PROPERTY_CHANGE, handle); 
      } 

      /** 
      * Handle scroll position changes 
      */ 
      private function handle(e:PropertyChangeEvent):void { 
       if (e.source == e.target && e.property == "verticalScrollPosition") 
        trace(e.property, "changed to", e.newValue); 
       if (e.source == e.target && e.property == "horizontalScrollPosition") 
        trace(e.property, "changed to", e.newValue); 
      } 
     ]]> 
    </fx:Script> 

    <s:Scroller id="myScroller" width="100" height="100"> 
     <s:Group> 
      <s:Button label="large content" width="300" height="300"/> 
     </s:Group> 
    </s:Scroller> 

</s:Application> 

Answer 2

slidePanel.slidesComponentsContainer.slidesList.scroller.addEventListener(
    TouchInteractionEvent.TOUCH_INTERACTION_START, 
    onSlideListVertScrollerTouchInteractionStart 
);