AS3-XML如何在加載xml時執行預加載器？

Question

在加載xml時，哪些代碼應該添加以顯示預加載器？或者我不需要有一個？

//Load gallery.xml 
var xmlLoader:URLLoader = new URLLoader(); 
var xmlData:XML = new XML(); 

xmlLoader.addEventListener(Event.COMPLETE, LoadXML); 
xmlLoader.load(new URLRequest("gallery.xml")); 

function LoadXML(e:Event):void 
{ 
    xmlData = new XML(e.target.data); 
    ParseProject(xmlData); 
} 

function ParseProject(projectInput:XML):void 
{ 
    trace("XML Output"); 
    trace("------------------------"); 

    var projectAttributes:XMLList = projectInput.project.attributes(); 

    for each (var projectName:XML in projectAttributes) 
    { 
     trace(projectName); 
     var projectDP:XMLList = projectInput.project.(@name == projectName).displayP; 
     trace(projectDP); 
    } 
} 

Answer 1

您可以偵聽ProgressEvent：

import flash.events.ProgressEvent 
xmlLoader.addEventListener(ProgressEvent.PROGRESS, _onProgress); 
function _onProgress(e:ProgressEvent):void { 
      //do whatever you need. 
    trace("loaded: ", e.bytesLoaded, " total: ", e.bytesTotal); 
} 

至於是否應該使用一個或沒有，這完全取決於你。一般來說，你最好讓用戶知道發生了什麼。