[etc]

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init();">
	<mx:Script>
		<![CDATA[
			import mx.core.UITextFormat;
			import mx.core.UITextField;
			import mx.containers.Canvas;
			
			private function init():void {
				var canvas:Canvas = new Canvas();
				addChild(canvas);
				canvas.width = 300;
				canvas.height = 100;
				var text:UITextField = new UITextField();
				var format:UITextFormat = new UITextFormat( Application.application.systemManager, 'Verdana', 20 );
				text.multiline = false;
				text.text = "TEXT";
				text.setTextFormat(format);
				text.antiAliasType = flash.text.AntiAliasType.ADVANCED;
				text.validateNow();
				canvas.addChild( text );				
			}
		]]>
	</mx:Script>
</mx:Application>

Замечательно работает.