I modified your code a little bit to use in a separate AS file for any chart type:

private function clickLegend(event:LegendMouseEvent, chart:ChartBase):void {
var ser:Series = findSeries(event.item.label, chart);
if(ser != null) {
ser.visible = (event.item as myLegendItem).selected;
}
}

private function findSeries(lbl:String, chart:ChartBase):Series {
for(var i:int = 0; i < chart.series.length;i++) {
if(chart.series[i].displayName == lbl) {
return chart.series[i];
}
}

return null;
}

My problem is when try to add a child (checkbox) in the createChildren() method the checkbox is placed above the legend Marker.

I want all 3 of them (check box, legend Marker (colour box) and the Name ) to be in a row..

Can anyone sugget a way to achieve this

private function clickLegend(event:MouseEvent):void{
for each(var legendItem:CustomLegendItem in legend.getChildren()){
var series:Series = findSeries(legendItem.label);
series.visible = legendItem.selected;
}
}

var lineSer:LineSeries = event.item.element as LineSeries;

I also found the following (using source insteaad of element) produces same results although I am not sure which one is more safer

var lineSer:LineSeries = event.item.source as LineSeries;

var lineSer:LineSeries = findSeries(event.item.label);

to:

var lineSer:LineSeries = event.item.element as Series;

This is a much more direct means, and less prone to errors. Hope this helps.

matt horn
flex docs