修改Flex chart中Legend的字体样式

FLEX的图表（CHART）中的Legend 的字体通过直接设置Style 并没有办法改变字体大小.

通过查资料发现了这个方法: 通过派生LegendItem类，并设置Legend的ItemClass属性来实现。
LegendItem 是Lengend 的元素, 就是里面一个一个的图示. 通过派生这个类, 就可以修改其相应的样式.

派生LegendItem 类, 并设置样式. 

BigFontLegendIte.as

// ActionScript file

package com

{

    import mx.charts.LegendItem;

    

    public class BigFontLegendItem extends LegendItem

    {

        public function BigFontLegendItem()

        {

            super();

            this.styleName = "ChineseFont";

        }

        

    }

}

2.在<s:Application>中添加样式：

<fx:Style>

        @namespace s "library://ns.adobe.com/flex/spark";

        @namespace mx "library://ns.adobe.com/flex/mx";

        .ChineseFont{

            fontFamily:"微软雅黑";

            fontSize:12;

            fontWeight:normal;

        }

    </fx:Style>

3. 在相应的Legend中指定legendItemClass="com.BigFontLegendItem"

<mx:Legend dataProvider="{linechart1}" direction="horizontal" legendItemClass="com.BigFontLegendItem"/>

<?xml version="1.0"?>
<!-- Simple example to demonstrate the LineChart and AreaChart controls. -->
<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" creationComplete="init()" >

<fx:Script>
<![CDATA[
import mx.charts.series.LineSeries;
import mx.collections.ArrayCollection;
import mx.utils.ColorUtil;

private var colorutil:ColorUtil ;
[Bindable]
private var expensesAC:ArrayCollection = new ArrayCollection( [
{ Month: "Jan", Profit: 2000, Expenses: 1500, Amount: 450 },
{ Month: "Feb", Profit: 1000, Expenses: 200, Amount: 600 },
{ Month: "Mar", Profit: 1500, Expenses: 500, Amount: 300 },
{ Month: "Apr", Profit: 1800, Expenses: 1200, Amount: 900 },
{ Month: "May", Profit: 2400, Expenses: 575, Amount: 500 } ]);

private function init():void
{
var array:Array = new Array();
for(var i:int =0;i<3;i++)
{
var line:LineSeries = new LineSeries();
line.setStyle("lineStroke",new SolidColorStroke(new uint("0xf00000"),4));
line.yField="Profit";
line.displayName="Profit";
array.push(line);
var c:ColorUtil = null;
}

linechart.series = array;
linechart.dataProvider = expensesAC;
linechart.showDataTips=true;

}

]]>
</fx:Script>
<fx:Style>
@namespace s "library://ns.adobe.com/flex/spark";
@namespace mx "library://ns.adobe.com/flex/mx";
.abc{
fontFamily:"微软雅黑";
fontSize:12;
fontWeight:normal;
color:green;
}

</fx:Style>

<fx:Declarations>

<!-- Define custom Strokes. -->
<mx:SolidColorStroke id = "s1" color="blue" weight="1" scaleMode="vertical" pixelHinting="false"/>
<mx:SolidColorStroke id = "s2" color="red" weight="2"/>
<mx:SolidColorStroke id = "s3" color="green" weight="2"/>
</fx:Declarations>

<mx:Panel title="LineChart and AreaChart Controls Example"
height="100%" width="100%" layout="horizontal">

<mx:LineChart id="linechart" height="100%" width="45%"
paddingLeft="5" paddingRight="5"
showDataTips="true" dataProvider="{expensesAC}">
<!--
<mx:horizontalAxis>
<mx:CategoryAxis categoryField="Month"/>
</mx:horizontalAxis>-->

<mx:series>
<mx:LineSeries yField="Profit" displayName="Profit" lineStroke="{s1}"/>
<mx:LineSeries yField="Expenses" displayName="Expenses" lineStroke="{s2}"/>
<mx:LineSeries yField="Amount" displayName="Amount" lineStroke="{s3}"/>
</mx:series>
</mx:LineChart>

<mx:Legend dataProvider="{linechart}" legendItemClass="LegendItemImpl"/>

</mx:Panel>
</s:Application>

package
{
import mx.charts.LegendItem;

public class LegendItemImpl extends LegendItem
{
public function LegendItemImpl()
{
super();
this.styleName= "abc";
}
}
}