Drawing On Chart But It's Disappearing

Question

I created a column chart and added an annotation element to it:
[code]
<mx:annotationElements>
        <mx:CartesianDataCanvas id="chartCanvas"/>
</mx:annotationElements>
[/code]
I added a creation complete method to draw on the canvas. The following function is called on creationComplete.
[code]  
protected function drawSteps():void
       trace("chartCanvas.width is: " + chartCanvas.width);
      chartCanvas.graphics.lineStyle(1, 0x000000, 0.5);
      chartCanvas.graphics.beginFill(0xd4e3f0, 0.5);
      chartCanvas.graphics.moveTo(chartCanvas.width/2, yAxisMax);
      chartCanvas.graphics.lineTo(chartCanvas.width/2, 0);
      chartCanvas.graphics.endFill();
[/code]
This works fine when the chart first loads but if I update the chart series the line goes away. I have added a call to the 'drawSteps()' function in my method that updates the chart series as well but it didn't work. I don't understand why changing the chart series would cause this to stop displaying though, especially considering I call it again when the series is changed. Can anyone help?

Answer 1

Other things may be drawn into the graphics object, and those things might clear what is there first.  It might be better to draw by overriding updateDisplayList()