Question

我在flex中创建了一个使用Actionscript3.0访问Java Web服务的应用程序。我在访问其中一个webservice方法时得到错误。该方法返回子对象列表我在ArrayCollection类对象中获取此对象列表。我的代码是： -

    [Bindable]
     private var photoFeed:Array; 
    public var user:SBTSWebService;

    public function initApp():void
    {
       user = new SBTSWebService();

       user.addSBTSWebServiceFaultEventListener(handleFaults);

    }

    public function displayString():void
    {
           // Instantiate a new Entry object.
           var newEntry:GetSBTSMobileAuthentication = new GetSBTSMobileAuthentication();
            newEntry.mobile=mobileno.text;
            newEntry.password=password.text;
            user.addgetSBTSMobileAuthenticationEventListener(authenticationResult);

            user.getSBTSMobileAuthentication(newEntry);

    }

    public function handleFaults(event:FaultEvent):void
    {
        Alert.show("A fault occured contacting the server. Fault message is: " + event.fault.faultString);
    }

    public function authenticationResult(event:GetSBTSMobileAuthenticationResultEvent):void
    {
        if(event.result != null) 
        {

           if(event.result._return > 0)
           {
             var UserId:int = event.result._return;
              getChildList(UserId);       
              viewstack2.selectedIndex=1;
           }
           else
           {
             Alert.show("Authentication fail");
           }


        }

    }
  public function getChildList(userId:int):void
  {
     var childEntry:GetSBTSMobileChildrenInfo = new GetSBTSMobileChildrenInfo();
     childEntry.UserId = userId;
     user.addgetSBTSMobileChildrenInfoEventListener(sbtsChildrenInfoResult);
     user.getSBTSMobileChildrenInfo(childEntry);
  }
   public function sbtsChildrenInfoResult(event:GetSBTSMobileChildrenInfoResultEvent):void
    {
        if(event.result != null && event.result._return!=null) 
        {

        photoFeed  = event.result._return as Array;
        childid.dataProvider = photoFeed; 

        }

    }


]]>

<mx:Move id="hideEffect"
    xTo="-500" />
<mx:Move id="showEffect"
    xFrom="500" />

<mx:Panel width="500" height="300"
    headerColors="[#000000,#FFFFFF]">

    <mx:TabNavigator id="viewstack2"
        selectedIndex="0"
        historyManagementEnabled="false"
        width="100%" height="100%">

        <mx:Form label="Login Form"
            hideEffect="{hideEffect}" showEffect="{showEffect}">
              <mx:FormItem>
                 <mx:TextInput id="mobileno"/>
              </mx:FormItem>
              <mx:FormItem>
                 <mx:TextInput id="password"/>
              </mx:FormItem>
              <mx:FormItem>
                 <mx:Button label="Login" click="displayString()"/>
              </mx:FormItem>
         </mx:Form>

        <mx:Form label="Child List"
            hideEffect="{hideEffect}" showEffect="{showEffect}">
           <mx:DataGrid id="childid" visible="false"/>



            <mx:Button label="click here to see location"
                click="viewstack2.selectedIndex=2" />
        </mx:Form>

        <mx:Form label="Bus Location"
            hideEffect="{hideEffect}" showEffect="{showEffect}">
            <mx:Text text="" />
        </mx:Form>
       <mx:Form label="Trace Path"
            hideEffect="{hideEffect}" showEffect="{showEffect}">
            <mx:Text text="" />
        </mx:Form>
    </mx:TabNavigator>

</mx:Panel>

我收到的错误如“TypeError：错误＃1009：无法访问空对象引用的属性或方法”。当行“photoFeed = event.result._return as Array;”时是编译。请帮我删除此错误。

Answer 1

由于您已经检查结果和result._return都不为null，因此您在该行上收到错误似乎很奇怪。线路更可能......

childid.dataProvider = photoFeed;

...导致错误，因为childid为空？这可能是因为您的选项卡导航器尚未创建第二个选项卡。尝试将creationPolicy =“all”添加到选项卡导航器中以确保它已创建。

<mx:TabNavigator id="viewstack2"
        selectedIndex="0"
        creationPolicy="all"
        historyManagementEnabled="false"
        width="100%" height="100%">

默认设置为“自动”，这意味着当您点击它们时，它只会创建默认面板以外的面板。

我在访问webservice时遇到问题

1 个答案: