Flex scroller皮肤的使用

flex4里引入了sparkSkin, spark包里的可视控件可以通过指定skinClass的值来修改控件的默认皮肤。

下面是一个如何自定义某个scrollbar的外观的例子。

新建一个flex project, 名字假设为myScrollerbar, 编辑mxml内容：

<?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" width="300" height="400" >
	<fx:Declarations>
		<!-- Place non-visual elements (e.g., services, value objects) here -->
 
	</fx:Declarations>		
	<s:Scroller percentWidth="100" percentHeight="100" id="scroller">
		<s:Group>
			<s:Rect percentWidth="100" height="800">
				<s:fill>
					<s:LinearGradient rotation='250'>
						<s:GradientEntry color='0x000000' ratio='0'/>
						<s:GradientEntry color='0xffffff' ratio='1'/>
					</s:LinearGradient>
				</s:fill>
			</s:Rect>
		</s:Group>		
	</s:Scroller>	
</s:Application>

编译运行程序，截图如下：

假设我们现在想改变右边verticalScrollbar的样子，并且已经准备好了所需要的图片：
up.png: 向上箭头的图片
down.png: 向下箭头的图片
thumb.png: 拖动条的图片

Scroller.verticalScrollbar 实际上是由4部分构成，
thumb：拖动条 (对应的类为spark.components.Button)
track: 拖动条下面的那个轨道 (对应的类为spark.components.Button)
decrementButton：向上箭头按钮(对应的类为spark.components.Button)
incrementButton: 向下箭头按钮(对应的类为spark.components.Button)

对整个verticalScrollbar我们需要一个mxml来定义其皮肤，里面每个部分也分别需要一个mxml来定义皮肤，那么我们一共需要5个mxml文件

下面是这5个mxml皮肤文件的定义：

1. MyVScrollBarSkin.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:SparkSkin xmlns:fx="http://ns.adobe.com/mxml/2009" 
			 xmlns:s="library://ns.adobe.com/flex/spark" 
			 xmlns:mx="library://ns.adobe.com/flex/mx" 
			 alpha.disabled="0.5"
			 alpha.inactive="0.5"
 
>
	<s:states>
		<s:State name="normal" />
		<s:State name="disabled" />
		<s:State name="inactive" />
	</s:states>
 
	<fx:Metadata>
		<![CDATA[ 
		[HostComponent("spark.components.VScrollBar")]
		]]>
	</fx:Metadata> 
 
 
	<s:Button id="track" top="30" bottom="30" focusEnabled="false" horizontalCenter="0"
			  skinClass="skins.MyVScrollBarTrackSkin" 
	/>
	<s:Button id="thumb" focusEnabled="false" horizontalCenter="0"
			  skinClass="skins.MyVScrollBarThumbSkin" 
 	/>
	<s:Button id="decrementButton" top="0"  focusEnabled="false" horizontalCenter="0"
			  skinClass="skins.MyVScrollBarDecrementButtonSkin" 
			  />
	<s:Button id="incrementButton" bottom="0"  focusEnabled="false" horizontalCenter="0"
			  skinClass="skins.MyVScrollBarIncrementButtonSkin" 
			  />
</s:SparkSkin>

2.MyVScrollBarThumbSkin.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:Skin xmlns:fx="http://ns.adobe.com/mxml/2009" 
		xmlns:s="library://ns.adobe.com/flex/spark" 
		xmlns:mx="library://ns.adobe.com/flex/mx"
		xmlns:pwg="com.perfectworld.gamelibs.pwgraphics.*"
 
		>
	<fx:Metadata>
		[HostComponent("spark.components.Button")]
	</fx:Metadata>
	<s:states>
		<s:State name="up" />
		<s:State name="over" />
		<s:State name="down" />
		<s:State name="disabled" />
	</s:states>
 
	<mx:Image  source="@Embed('thumb.png')" />
 
</s:Skin>

3.MyVScrollBarTrackSkin.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:Skin xmlns:fx="http://ns.adobe.com/mxml/2009" 
		xmlns:s="library://ns.adobe.com/flex/spark" 
		xmlns:mx="library://ns.adobe.com/flex/mx"
		xmlns:pwg="com.perfectworld.gamelibs.pwgraphics.*"
 
		>
	<fx:Metadata>
		[HostComponent("spark.components.Button")]
	</fx:Metadata>
	<s:states>
		<s:State name="up" />
		<s:State name="over" />
		<s:State name="down" />
		<s:State name="disabled" />
	</s:states>
 
	<s:Rect top="0" bottom="0" width="29">
		<s:fill>
			<s:SolidColor  color="0x131313" alpha="0.3" />
		</s:fill>
	</s:Rect>
 
</s:Skin>

4.MyVScrollBarDecrementButtonSkin.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:Skin xmlns:fx="http://ns.adobe.com/mxml/2009" 
		xmlns:s="library://ns.adobe.com/flex/spark" 
		xmlns:mx="library://ns.adobe.com/flex/mx"
		xmlns:pwg="com.perfectworld.gamelibs.pwgraphics.*"
		>
	<fx:Metadata>
		[HostComponent("spark.components.Button")]
	</fx:Metadata>
	<s:states>
		<s:State name="up" />
		<s:State name="over" />
		<s:State name="down" />
		<s:State name="disabled" />
	</s:states>
	<mx:Image  source="@Embed('up.png')"/>	
</s:Skin>

5. MyVScrollBarIncrementButtonSkin.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:Skin xmlns:fx="http://ns.adobe.com/mxml/2009" 
		xmlns:s="library://ns.adobe.com/flex/spark" 
		xmlns:mx="library://ns.adobe.com/flex/mx"
		xmlns:pwg="com.perfectworld.gamelibs.pwgraphics.*"
		>
	<fx:Metadata>
		[HostComponent("spark.components.Button")]
	</fx:Metadata>
	<s:states>
		<s:State name="up" />
		<s:State name="over" />
		<s:State name="down" />
		<s:State name="disabled" />
	</s:states>
 
	<mx:Image  source="@Embed('down.png')"/>	
</s:Skin>

皮肤文件定义好了，那么现在修改mySCrollbar.mxml为 scroller.verticalScrollbar指定skinClass:

<?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" width="300" height="400" creationComplete="init()">
	<fx:Declarations>
		<!-- Place non-visual elements (e.g., services, value objects) here -->
 
	</fx:Declarations>
	<fx:Script>
		<![CDATA[
			import skins.MyVScrollBarSkin;
			private function init():void {
				scroller.verticalScrollBar.setStyle("skinClass", MyVScrollBarSkin);
				scroller.verticalScrollBar.setStyle( "fixedThumbSize", true);
			}
		]]>
	</fx:Script>
 
	<s:Scroller percentWidth="100" percentHeight="100" id="scroller">
		<s:Group>
			<s:Rect percentWidth="100" height="800">
				<s:fill>
					<s:LinearGradient rotation='250'>
						<s:GradientEntry color='0x000000' ratio='0'/>
						<s:GradientEntry color='0xffffff' ratio='1'/>
					</s:LinearGradient>
				</s:fill>
			</s:Rect>
		</s:Group>		
	</s:Scroller>	
</s:Application>

主要是加了这2行代码：

scroller.verticalScrollBar.setStyle("skinClass", MyVScrollBarSkin);
scroller.verticalScrollBar.setStyle( "fixedThumbSize", true);

最后的样子如下：

Flex scroller皮肤的使用

Flex4 scroller 自定义皮肤