[转]访问ItemRenderer的方法，备案
http://uh.9ria.com/space-12147-do-blog-id-590.html

use namespace mx_internal;

private function keyHandler(event:KeyboardEvent):void{
(dataGrid.rendererArray[dataGrid.selectedIndex+1][2] as RadioListCanvas).button.dispatchEvent(new MouseEvent(MouseEvent.CLICK))
}