ActionScript - 在switch语句中使用“is”比较？

Question

我有许多相同的自定义类的对象，另一个自定义类的另一些对象。我想创建一个switch语句来确定对象属于哪个类。下面的代码不能编译，所以我不确定这是否可能。是使用if语句的唯一选择吗？

function mouseClickEventHandler(evt:MouseEvent):void 
    { 
    switch (evt.currentTarget) 
      { 
      case (is customClassA): trace("is instance of customClassA"); break 
      case (is customClassB): trace("is instance of customClassB"); 
      } 
    } 

Answer 1

这应该工作：

function mouseClickEventHandler (evt:MouseEvent):void 
{ 
    switch (evt.currentTarget.constructor) 
    { 
     case CustomClassA: 
      trace("is instance of customClassA"); 
      break; 

     case CustomClassB: 
      trace("is instance of customClassB"); 
      break; 
    } 
} 

见Object.constructor。

Answer 2

function clickHandler (event:MouseEvent):void 
{ 
    var target:Object = event.currentTarget; 
    switch (true) 
    { 
     case (target is CustomClassA): 
      trace("is instance of customClassA"); 
      break; 

     case (target is CustomClassB): 
      trace("is instance of customClassB"); 
      break; 
    } 
}

不知道是否括号需要