package {

        import flash.display.Loader;
        import flash.net.URLRequest;
        import flash.utils.ByteArray;
        import flash.events.Event;
        import flash.events.ProgressEvent;
        import flash.events.EventDispatcher;
        import flash.system.LoaderContext;

        public class ClassLoader extends EventDispatcher{
  
           public var url:String;
           public var loader:Loader;
          
           //构造函数
           public function ClassLoader(obj:Object = null,lc:LoaderContext = null) {
              if(obj != null){
                if(obj is ByteArray){
                  loadBytes(obj as ByteArray,lc);
                }else if(obj is String){
                  load(obj as String,lc);
                }else{
                  //throw new Error("参数错误，构造函数第一参数只接受ByteArray或String");
                }
              }
           }
  
            //加载
           public function load(_url:String,lc:LoaderContext = null):void{
              url = _url;
              loader = new Loader;
              loader.load(new URLRequest(url),lc);
              addEvent();
            }
  
           //加载字节
           public function loadBytes(bytes:ByteArray,lc:LoaderContext = null):void{
              loader = new Loader;
              loader.loadBytes(bytes,lc);
              addEvent();
            }
  
          //开始侦听
            private function addEvent():void{
              loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS,progressFun);
              loader.contentLoaderInfo.addEventListener(Event.COMPLETE,completeFun);
            }
  
            //结束侦听
            private function delEvent():void{
              loader.contentLoaderInfo.removeEventListener(ProgressEvent.PROGRESS,progressFun);
              loader.contentLoaderInfo.removeEventListener(Event.COMPLETE,completeFun);
           }
  
            //加载成功，发布成功事件
            private function completeFun(e:Event):void {
              delEvent();
              dispatchEvent(e);
            }
  
           //加载过程
            private function progressFun(e:ProgressEvent):void{
              dispatchEvent(e);
            }
  
            //获取定义
            public function getClass(className:String):Object {
              return loader.contentLoaderInfo.applicationDomain.getDefinition(className);
           }
  
           //是否含有该定义
            public function hasClass(className:String):Boolean {
              return loader.contentLoaderInfo.applicationDomain.hasDefinition(className);
            }
  
            //清除
           public function clear():void{
              loader.unload();
              loader = null;
           }
         }
        }