Using two constraint columns to align a pair of buttons
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Canvas width="100%" height="100%"> <mx:constraintColumns> <mx:ConstraintColumn id="col1" width="200" /> <mx:ConstraintColumn id="col2" width="50" /> </mx:constraintColumns> <mx:Button label="Button 1" left="col1:0" /> <mx:Button label="Button 2" left="col2:0" /> </mx:Canvas> </mx:Application>