Get position, width and height of the actual chart

I want to place a container (transparent red) on top of my chart.

How do I get the origin (point A), width and height of开发者_如何转开发 this area?

http://img88.imageshack.us/img88/4558/flexchart01.png http://img88.imageshack.us/img88/4558/flexchart01.png

So if you wanted to place this container as a background image (I realize this isn't quite what you want to do) you could place a 100% width and height canvas in the tag of the canvas. I believe there is a similar property that goes on top of the chart, maybe you can do something with this?

Edit: It is annotationElements that you want:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" minWidth="955" minHeight="600">
    <mx:Script><![CDATA[
        import mx.collections.ArrayCollection;
        [Bindable]
        public var expenses: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}
        ]);
    ]]></mx:Script>
    <mx:Panel title="Line Chart">
        <mx:LineChart id="myChart" 
                      dataProvider="{expenses}" 
                      showDataTips="true"
                      >
            <mx:horizontalAxis>
                <mx:CategoryAxis 
                    dataProvider="{expenses}" 
                    categoryField="Month"
                    />
            </mx:horizontalAxis>
            <mx:series>
                <mx:LineSeries 
                    yField="Profit" 
                    displayName="Profit"
                    />
                <mx:LineSeries 
                    yField="Expenses" 
                    displayName="Expenses"
                    />
            </mx:series>
            <mx:annotationElements>
                <mx:Canvas backgroundAlpha=".5" backgroundColor="0xff0000" />
            </mx:annotationElements>
        </mx:LineChart>
        <mx:Legend dataProvider="{myChart}"/>
    </mx:Panel>

</mx:Application>