As3.0中的反射

var txtClass:Class = getDefinitionByName("flash.text.TextField") as Class;
var txtInstance:TextField = new txtClass() as TextField;
txtInstance.text = "通过反射动态创建的TextField";
txtInstance.width = stage.stageWidth;
addChild(txtInstance);

package  {
	
	import flash.display.Sprite;
	
	public class MyClass extends Sprite{

		public function MyClass() {
			
			trace("MyClass is created.")
		}
		
		public function HelloWorld(msg:String){
			trace("MyClass.HelloWorld is called. msg =" + msg);
		}

	}
	
}

var aClass:Class = getDefinitionByName("MyClass") as Class;
var myClassInstance:MyClass = new aClass() as MyClass;
myClassInstance.HelloWorld("菩提树下的杨过");