AS3检查类是否扩展了另一个类

package {
 import flash.display.Sprite;



public class Main extends Sprite {
  public function Main() {
   var bar:Bar=new Bar();
   trace("bar is Bar",bar is Bar);//true
   trace("bar is Foo:",bar is Foo);//true
   trace("bar is IKingKong:",bar is IKingKong);//true
   trace(describeType(bar));
   //<type name="Main.as$0::Bar" base="Main.as$0::Foo" isDynamic="false" isFinal="false" isStatic="false">
   //<extendsClass type="Main.as$0::Foo"/>
   //<extendsClass type="Object"/>
   //<implementsInterface type="Main.as$0::IKingKong"/>
   //</type>
  }
 }
}
interface IKingKong{}
class Foo implements IKingKong{}
class Bar extends Foo{}

你可以这样做:

class Foo {}
class Bar extends Foo {}

var object = new Bar();

if (object as Foo != null) { /* is executed */ }

使用接口或abtract类,您应该能够做到这一点

 var object:Foo = new Bar();
 if (object is Foo){ /* is executed */ }

 //or
 var object:IFoo = new Bar();
 if (object is IFoo){ /* is executed */ }

package
{   
import flash.display.Sprite;
import flash.utils.getQualifiedSuperclassName;

public class Test extends Sprite
    {
    public function Test()
        {
        trace(getQualifiedSuperclassName(this)); //returns "flash.display::Sprite"
        }
    }
}