Flex - 如何在另一個組件中定義一個功能？

Question

我是一個完整的Flex/Flash noob，運行Adobe Flash Builder 4 Beta 2.我有一個主要組件，需要能夠調用幾個彈出窗口，每個彈出窗口大多都相同，除了一個函數和幾個標籤。顯然，我更喜歡能夠定義這個函數，並在調用彈出窗口時更改這些標籤，而不是使用幾乎相同的代碼來創建大量的.mxml文件，我只是不知道該怎麼做。我想出瞭如何改變標籤，但不知道如何重新定義這個功能。

爲簡單起見，假設我的代碼如下所示：

main.mxml：

<?xml version="1.0" encoding="utf-8"?> 
    <mx:Module xmlns:fx="http://ns.adobe.com/mxml/2009" :s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/halo" creationComplete="init()"> 
     <fx:Script> 
      <![CDATA[ 
       import mx.controls.Alert; 
       import mx.managers.PopUpManager; 

       protected function init():void 
       { 
        var alertWindow:IFlexDisplayObject = PopUpManager.createPopUp(FlexGlobals.topLevelApplication as DisplayObject, popup, true); 
        PopUpManager.centerPopUp(alertWindow); 
        var popInstance:transmitRoundPop = alertWindow as transmitRoundPop; 
        popInstance.btnTest.label = "NEW"; 
       } 
      ]]> 
     </fx:Script> 
    </mx:Module> 

popup.mxml：

<?xml version="1.0" encoding="utf-8"?> 
    <s:Group xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/halo" width="400" height="300" xmlns:flash="services.flash.*"> 
     <fx:Script> 
      <![CDATA[ 
       import mx.controls.Alert; 
       import mx.managers.PopUpManager; 

       public function test():void 
       { 
        Alert.show("ORIGINAL"); 
        PopUpManager.removePopUp(this); 
       } 
      ]]> 
     </fx:Script> 
     <s:Panel x="10" y="10" width="380" height="280" title="Test" id="pnlTest"> 
       <s:Button x="131" y="104" label="OLD" id="btnTest" click="test()"/> 
     </s:Panel> 
    </s:Group> 

現在說我要改變test()在在main.mxml中調用它時popup.mxml ......我該怎麼做？請包括詳細信息...請記住我是一個菜鳥:-)

Answer 1

當然，張貼的想法浮現在我腦海中的問題之後。我想我會在這裏發佈解決方案，而不是僅僅刪除問題，以防其他人幫助。

我只是把test()出完全popup.mxml和main.mxml修改init()看起來像這樣：

protected function init():void 
{ 
    var alertWindow:IFlexDisplayObject = PopUpManager.createPopUp(FlexGlobals.topLevelApplication as DisplayObject, popup, true); 
    PopUpManager.centerPopUp(alertWindow); 
    var popInstance:transmitRoundPop = alertWindow as transmitRoundPop; 
    popInstance.btnTest.label = "NEW"; 
    popInstance.btnTest.addEventListener("click", function():void { Alert.show("REDEFINED"); }); 
} 

Answer 2

如果我得到你問的問題，你可以使測試（）一個函數變量，並給它的公共訪問，以便其他組件可以改變它。

<fx:Script> 
     <![CDATA[ 
      import mx.controls.Alert; 
      import mx.managers.PopUpManager; 

      // "test" is now a function variable, 
      // you change it just like any other variable, 
      // but you can call it as well, just like before. 
      public var test:Function; 

      public function defaultTest():void 
      { 
       Alert.show("ORIGINAL"); 
       PopUpManager.removePopUp(this); 
      } 

      protected function init():void 
      { 
      // Setting a default value for test 
      // otherwise it would give you an error when calling 
      // an unassigned function variable. 
       this.test = defaultTest; 
       ... 
      } 
     ]]> 
    </fx:Script> 

現在，在另一個組件：

public function mainTest():void 
{ 
    ... 
} 

... 
myPopup.test = mainTest; // setting the variable, note that there are no parentheses. 
myPopup.test(); // running the function, note that there are now parentheses.