由网友(憋不住hold住！)分享简介：在我的应用程序，我使用的是Scroller零件。我似乎无法找出哪个事件我应该建立一个监听器上，才能知道什么时候滚动内容。我试过 Event.CHANGE 在 Scroller.verticalScrollBar 属性，但显然该事件不会触发当用户滚动带鼠标滚轮或箭头键。Within my application I'm...

在我的应用程序，我使用的是Scroller零件。我似乎无法找出哪个事件我应该建立一个监听器上，才能知道什么时候滚动内容。我试过 Event.CHANGE 在 Scroller.verticalScrollBar 属性，但显然该事件不会触发当用户滚动带鼠标滚轮或箭头键。

Within my application I'm using a Scroller component. I can't seem to figure out which event I should set up a listener on in order to know when content is scrolled. I tried Event.CHANGE on Scroller.verticalScrollBar property but apparently that event doesn't fire when the user scrolls with a mouse wheel or arrow keys.

推荐答案

您可以侦听滚轮的视propertyChange事件。以下是演示如何这可能是做了一个应用程序：

You can listen for the propertyChange event on the viewport of the Scroller. Here is an application that demonstrates how this might be done:

<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>