be easy

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
			   xmlns:s="library://ns.adobe.com/flex/spark" 
			   xmlns:mx="library://ns.adobe.com/flex/mx" 
			   minWidth="955" minHeight="600">
	<fx:Script>
		<![CDATA[
		import spark.core.NavigationUnit;
 
		/**
		 * 上一页
		 */
		private function prePageHandler():void
		{
			smp.valueBy = hGroup.getHorizontalScrollPositionDelta(NavigationUnit.PAGE_LEFT);
			anmiate.play();
		}
 
		/**
		 * 下一页
		 */
		private function nextPageHandler():void
		{
			smp.valueBy = hGroup.getHorizontalScrollPositionDelta(NavigationUnit.PAGE_RIGHT);
			anmiate.play();
		}
 
		]]>
	</fx:Script>
	<fx:Declarations>
		<s:Animate id="anmiate" target="{hGroup}" duration="800">
			<s:motionPaths>
				<s:SimpleMotionPath id="smp" property="horizontalScrollPosition"/>
			</s:motionPaths>
		</s:Animate>
	</fx:Declarations>
	<s:Panel title="Flex4 Group新特性">
		<s:HGroup id="hGroup" gap="10" height="100" width="320" clipAndEnableScrolling="true">
			<s:Button width="100" height="100" label="1" fontSize="30"/>
			<s:Button width="100" height="100" label="2" fontSize="30"/>
			<s:Button width="100" height="100" label="3" fontSize="30"/>
			<s:Button width="100" height="100" label="4" fontSize="30"/>
			<s:Button width="100" height="100" label="5" fontSize="30"/>
			<s:Button width="100" height="100" label="6" fontSize="30"/>
			<s:Button width="100" height="100" label="7" fontSize="30"/>
		</s:HGroup>
		<s:controlBarContent>
			<s:HGroup width="100%" horizontalAlign="center">
				<s:Button label="上一页" click="prePageHandler()"/>
				<s:Button label="下一页" click="nextPageHandler()"/>
			</s:HGroup>
		</s:controlBarContent>
	</s:Panel>
</s:Application>

/**
 * 主程序初始化时对systemManager进行侦听
 */
public function init():void
{
	systemManager.addEventListener(FlexEvent.IDLE, idleHandler);
}
 
/**
 * idle事件处理
 */
private function idleHandler(event:FlexEvent):void
{
	var idleCounter:int = systemManager.mx_internal::idleCounter;
	if( idleCounter >= 900)// 100毫秒一次，900就等于90秒
		systmeIdle();
}
 
/**
 * 发送系统空闲消息
 */
private function systmeIdle():void
{
	// TO DO ...
}

// 先把名导入
import mx.core.mx_internal;
 
// 对象.命名空间::属性名
systemManager.mx_internal::idleCounter;

package org.beasy.binding.utils
{
	import mx.binding.utils.ChangeWatcher;
	import mx.styles.IStyleClient;
 
	/**
	 * Flex的绑定功能为我们的日常提供很多的方便
	 * 但是Flex只提供了属性的绑定类->BindingUtils;
	 * 如果要实现绑定控件的Style还要自己用ChangeWatcher去侦听事件
	 * 有了StyleBindingUtils这一切将变的简单
	 * StyleBindingUtils封装了ChangeWatcher进行了Style的绑定实现,
	 * 为您的开发提供了更多方便和快捷
	 * @author Marco
	 */
	public class StyleBindingUtils
	{
		public function StyleBindingUtils()
		{
		}
 
		public static function bindStyle(
			site:IStyleClient, prop:String,
			host:Object, chain:Object,
			commitOnly:Boolean = false):ChangeWatcher
		{
			var w:ChangeWatcher =
				ChangeWatcher.watch(host, chain, null, commitOnly);
 
			if(w != null )
			{
				var assign:Function = function(event:*):void
				{
					site.setStyle(prop, w.getValue());
				}
				w.setHandler( assign );
				assign(null);
			}
 
			return w;
		}
 
	}
}