同时显示Line和Column两种Chart

<mx:LineChart id="linechart" color="0x323232" width="100%" height="100%"
	showDataTips="true" dataProvider="{initLocator.chartArrayCollection}"
	dataTipFunction="renderLineTips">
	
	<mx:horizontalAxis>
        <mx:CategoryAxis categoryField="xAxis" title="Date"/>
    </mx:horizontalAxis>

    <mx:series>
        <mx:ColumnSeries yField="milestoneValue" maxColumnWidth="1" />
        <mx:LineSeries yField="yAxis" form="curve" displayName="Effort"/>
    </mx:series>
</mx:LineChart>