未定義的屬性AS3

Question

package{ 
import flash.display.MovieClip; 
import flash.utils.Timer; 
import flash.events.TimerEvent; 
import flash.events.MouseEvent; 

public class Main extends MovieClip{ 

    public var ability1,ability3:Ability; 

    public function Main(){ 

     var ability1 = new Ability(30,30,"Ability Name","...",5,false); 
     addChild(ability1);   
     var ability2 = new Ability(60,30,"Ability Name2","...",3,false); 
     addChild(ability2); 
     var ability3 = new Ability(45,60,"Ability Name3","...",5,true); 
     addChild(ability3); 
     stage.addEventListener(MouseEvent.CLICK, Check);  

     trace(ability1.Points); //outputs the value 

    } 
    public function Check(event:MouseEvent):void{ 

     trace(ability1.Points); //outputs error 

    } 
}} 

第二個跟蹤給出了這個錯誤：「TypeError：Error＃1010：一個術語未定義，沒有任何屬性在Main/Check（）」你能指出我至少嗎？

謝謝。

Answer 1

通過在Main方法中使用var語句，可以將實例分配給僅在該方法範圍內的局部變量。更新您的代碼如下，你應該得到你期望的結果：

package{ 
    import flash.display.MovieClip; 
    import flash.utils.Timer; 
    import flash.events.TimerEvent; 
    import flash.events.MouseEvent; 

    public class Main extends MovieClip{ 

     public var ability1:Ability; 
     public var ability3:Ability; 

     public function Main(){ 

      // I'm a local property scoped only to this method 
      var ability2 = new Ability(60,30,"Ability Name2","...",3,false); 
      addChild(ability2); 

      // We're instance properties and can be accessed from any method 
      // in the class (and from outside the class as well) 
      ability1 = new Ability(30,30,"Ability Name","...",5,false); 
      addChild(ability1); 

      ability3 = new Ability(45,60,"Ability Name3","...",5,true); 
      addChild(ability3); 
      stage.addEventListener(MouseEvent.CLICK, Check);  

      trace(ability1.Points); //outputs the value 

     } 
     public function Check(event:MouseEvent):void{ 

      trace(ability1.Points); //outputs the value 
      trace(ability3.Points); //outputs the other value 
     } 
    } 
}