在LineChart中加入label

package
{
	import flash.display.Graphics;
	import flash.geom.Rectangle;
	
	import mx.charts.chartClasses.LegendData;
	import mx.charts.series.LineSeries;
	import mx.charts.series.items.LineSeriesItem;
	import mx.controls.Label;
	import mx.core.IDataRenderer;
	import mx.core.UIComponent;
	import mx.graphics.Stroke;

	public class LineRenderer extends UIComponent implements IDataRenderer
	{
		private var _label:Label;
		private var _yField:String;
		private var _color:Number;
		
		private var _chartItem:LineSeriesItem;
	
	public function LineRenderer():void
	{
		super();
		_label = new Label();
		addChild(_label);
	}

	public function get data():Object
	{
		return _chartItem;
	}

	public function set data(value:Object):void
	{
		if (_chartItem == value)
			return;
		if(value is LineSeriesItem) {
			_chartItem = LineSeriesItem(value);
			_label.text = _chartItem.yValue.toString()+"%";
			_color = Stroke(LineSeries(_chartItem.element).getStyle("lineStroke")).color;
			_label.setStyle("color",_color);
		} else if(value is LegendData) {
			_color = Stroke(LineSeries(LegendData(value).element).getStyle("lineStroke")).color;
		}
	}

	override protected function updateDisplayList(unscaledWidth:Number,
												  unscaledHeight:Number):void
	{
		super.updateDisplayList(unscaledWidth, unscaledHeight);
		var rc:Rectangle = new Rectangle(0, 0, width , height );
		
		var g:Graphics = graphics;
		g.clear();		
		g.moveTo(rc.left,rc.top);
		g.beginFill(_color);
		g.drawCircle(4,4,1);
		g.endFill();
		
		_label.setActualSize(_label.getExplicitOrMeasuredWidth(),_label.getExplicitOrMeasuredHeight());
		_label.move(unscaledWidth ,
					unscaledHeight);
	}
		
	}
}

在LineSeries里使用itemRenderer引用