2011-01-27 58 views
0

以下是我的代碼。這仍在進行中;所以,你會看到一些內容爲空的函數。另外,這是我的第一個Flex應用程序;請多多包涵。如何檢查Flex中動態生成的單選按鈕和複選框上的用戶選擇?

這是一個測驗應用程序,它可以從ColdFusion Web服務獲取每個問題的問題和答案。有三種類型的問題:真或假,單選的多選,以及多選的多選。因此,根據問題類型,應用程序會動態生成適當數量的單選按鈕或複選框供用戶選擇。我得到了這些工作。我遇到的問題是,我不確定如何檢查用戶實際選擇的內容。在其他網站的一些其他論壇和帖子中,它表示我可以使用event.currentTarget.selectedValue來獲取用戶選擇。但是當我真的這樣做時,我得到了一個運行時錯誤,說:「在mx.controls.FormItem上找不到屬性selectedValue,並且沒有默認值。」我的問題是,我需要做什麼來捕獲用戶選擇?

由於提前,

<?xml version="1.0" encoding="utf-8"?> 
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
    xmlns:s="library://ns.adobe.com/flex/spark" 
    xmlns:mx="library://ns.adobe.com/flex/mx" 
    creationComplete="initVars()"> 
    <fx:Declarations>  
     <s:RemoteObject id="CFCertService" destination="ColdFusion" source="CFCertExam.cfquiz"> 
     <s:method name="returnQuestions" result="resultHandler(event)"/> 
     <s:method name="returnAnswers" result="answerHandler(event)"/> 
     </s:RemoteObject> 
    </fx:Declarations> 
    <fx:Script> 
     <![CDATA[ 
      import mx.collections.ArrayCollection; 
      import mx.containers.FormItem; 
      import mx.controls.Alert; 
      import mx.controls.CheckBox; 
      import mx.controls.RadioButton; 
      import mx.rpc.events.ResultEvent; 
      import mx.rpc.remoting.RemoteObject; 

      [Bindable] 
      private var questionArray:ArrayCollection; 
      private var questionType:String; 
      private var answerItem:FormItem; 

      [Bindable] 
      private var currentQuestionCounter:int; 

      [Bindable] 
      private var answerArray:ArrayCollection; 
      private var myOptionButton:RadioButton = new RadioButton(); 
      private var myOptionButton2:RadioButton = new RadioButton(); 

      private function initVars():void { 
       currentQuestionCounter = 0; 
       btnPrev.enabled = false; 
       btnNext.enabled = false; 
      } 

      private function answerHandler(event:ResultEvent):void { 
       answerArray = event.result as ArrayCollection; 
       var i:int; 
       answerForm.removeAllChildren(); 
       answerItem = new FormItem(); 
       answerForm.addChild(answerItem); 

       switch (questionType) { 
        case "True or False": 
        { 
          myOptionButton.label = "True"; 
          if (answerArray.getItemAt(0).Answer_Choice == "True") { 
           myOptionButton.value = 1; 
          } else { 
           myOptionButton.value = 0; 
          } 


          answerItem.addChild(myOptionButton);        

          myOptionButton2.label = "False";    
          if (answerArray.getItemAt(0).Answer_Choice == "False") { 
           myOptionButton2.value = 1; 
          } else { 
           myOptionButton2.value = 0; 
          } 
          answerItem.addChild(myOptionButton2);      
          answerItem.addEventListener(MouseEvent.CLICK, selectionHandler);        
          break; 
        } 

        case "Multiple Choice (Single Selection)": 
        { 
         for (i=0; i<answerArray.length; i++) { 
          var myOptionButton1:RadioButton = new RadioButton(); 
          myOptionButton1.label = answerArray.getItemAt(i).Answer_Choice; 
          if (answerArray.getItemAt(i).Corect_Flag == "1") { 
           myOptionButton1.value = 1; 
          } else { 
           myOptionButton1.value = 0; 
          }       
          answerItem.addChild(myOptionButton1);       
         } 
         break; 
        } 

        case "Multiple Choice (Multiple Selection)": 
        { 
         for (i=0; i<answerArray.length; i++) { 
          var myCheckBox:CheckBox = new CheckBox(); 
          myCheckBox.label = answerArray.getItemAt(i).Answer_Choice;    
          answerItem.addChild(myCheckBox);        
         } 
         break; 
        } 
       } 

       answerForm.x = 380; 
       answerForm.y = 200; 
      } 

      private function selectionHandler(event:MouseEvent):void { 
       Alert.show(event.currentTarget.toString()); 
      } 

      private function resultHandler(event:ResultEvent):void { 
       questionArray = event.result as ArrayCollection; 

       txt1Questions.htmlText = questionArray.getItemAt(currentQuestionCounter).Question_Text; 
       questionType = questionArray.getItemAt(currentQuestionCounter).Question_Type; 
       btnNext.enabled = true; 
       CFCertService.returnAnswers(questionArray.getItemAt(currentQuestionCounter).Question_ID); 
      } 

      private function buttonEventHandler():void { 
       CFCertService.returnQuestions(); 
       btnStartExam.enabled = false; 
      } 

      private function btnPrevEventHandler():void { 
       currentQuestionCounter--; 
       if (currentQuestionCounter == 0) { 
        btnPrev.enabled = false; 
       } 
       if (currentQuestionCounter < questionArray.length) { 
        btnNext.enabled = true; 
       } 
       txt1Questions.htmlText = questionArray.getItemAt(currentQuestionCounter).Question_Text; 
       questionType = questionArray.getItemAt(currentQuestionCounter).Question_Type; 
       CFCertService.returnAnswers(questionArray.getItemAt(currentQuestionCounter).Question_ID); 

      } 

      private function answerReturnHandler(questionIndex:int):void { 
      } 

      private function btnNextEventHandler():void { 
       currentQuestionCounter++; 

       if (currentQuestionCounter > 0) { 
        btnPrev.enabled = true; 
       } 
       if (currentQuestionCounter >= (questionArray.length - 1)) { 
        btnNext.enabled = false; 
       } 
       txt1Questions.htmlText = questionArray.getItemAt(currentQuestionCounter).Question_Text; 
       questionType = questionArray.getItemAt(currentQuestionCounter).Question_Type; 
       CFCertService.returnAnswers(questionArray.getItemAt(currentQuestionCounter).Question_ID); 

      } 
     ]]> 
    </fx:Script> 

    <mx:Text id="txt1Questions" x="129" y="124"/> 
    <s:Button id="btnStartExam" label="Start Exam" click="buttonEventHandler()" x="370" y="54"/> 

    <mx:Form id="answerForm"/> 
    <s:Button x="129" y="436" label="Previous" id="btnPrev" click="btnPrevEventHandler()" enabled="false"/> 
    <s:Button x="642" y="436" label="Next" id="btnNext" click="btnNextEventHandler()" enabled="false"/> 

</s:Application> 
+2

您應該始終將代碼格式化爲代碼,否則XML標籤根本不會顯示。使用{}按鈕或縮進4個空格。而且,只是粘貼你的整個程序很可能無助於獲得答案。將問題縮小到與問題相關的那些代碼行 - 沒有人想要重新創建軟件來理解你所要求的內容。 – weltraumpirat 2011-01-27 17:03:35

+0

我點擊了代碼示例圖標,然後我在那裏粘貼了代碼。我應該點擊其他圖標嗎?就粘貼整個程序而言,已經很晚了,我沒有想到。對於那個很抱歉。 – 2011-01-27 23:08:21

回答

1

在你的代碼的問題是,currentTarget引用您添加事件監聽器,你加入的FormItem而不是單選按鈕的UIComponent。

兩個選項

  1. 如果你想繼續到事件監聽器添加到FormItem中,你應該使用target而不是currentTarget獲得參考,以實際的項目點擊,而不是的UIComponent與聽衆對話。但是,您應該知道,如果您向FormItem添加了其他任何內容(例如,Labels,RichText等),那麼這些項目在點擊時也會觸發事件偵聽器。

  2. 另一個選項是添加事件監聽器(它們都可以使用selectionHandler)到每個RadioButton,然後currentTarget將正常工作。

另外,對於那些只允許單個選擇的問題,您可能需要使用RadioButtonGroup。然後你只需要使用RadioButtonGroup上的Event.CHANGE來觸發你的selectionHandler

其他資源

退房的周系列的video on event bubbling從Flex。

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