Question

在AS3中，我试图检查一个对象是一个实例，还是扩展一个特定的类。如果对象是if (object is ClassName)的实例，则使用类似ClassName的内容可以正常工作，但如果它是扩展 ClassName的类的实例则不行。

伪代码示例：

class Foo {}
class Bar extends Foo {}

var object = new Bar();

if (object is Foo){ /* not executed */ }
if (object is Foo){ /* is executed */ }

我想要类似的东西：

class Foo {}
class Bar extends Foo {}

var object = new Bar();

if (object is Foo){ /* is executed */ }

任何想法？

Answer 1

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{}

Answer 2

你可以这样做：

class Foo {}
class Bar extends Foo {}

var object = new Bar();

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

Answer 3

使用接口或抽象类，您应该可以执行此操作

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

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

Answer 4

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

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

AS3检查类是否扩展了另一个类

4 个答案: