封装加载xml文件和图片的方法

封装加载xml文件和图片的方法，方便以后使用

  注意：在加载时一定要进行错误处理

/**
         * 加载xml文件
         * @param url
         * @param callback
         * protected function init(event:FlexEvent):void
            {
                LoaderHelper.loadXML( "test.xml", onXMLLoaded );
            }
            
            private function onXMLLoaded(xml:XML):void
            {
                trace( xml.toString() );
            }
         * 
         */        
        public static function loadXML(url:String, callback:Function):void
        {
            var loader:URLLoader = new URLLoader();
            loader.load( new URLRequest( url ) );
            //处理加载错误
            loader.addEventListener(IOErrorEvent.IO_ERROR, onError);
            loader.addEventListener(Event.COMPLETE, function(event:Event):void{
                callback( new XML( loader.data ) );
            } );
        }
        
        /**
         * 加载图片
         * @param url
         * @param callback
         * 
         * protected function init(event:FlexEvent):void
            {
                LoaderHelper.loadImage( "test.png", onImageLoaded );
            }
            
            private function onXMLLoaded(xml:XML):void
            {
                trace( xml.toString() );
            }
         */        
        public static function loadImage(url:String, callback:Function):void
        {
            var loader:Loader = new Loader();
            loader.load( new URLRequest( url ) );
            //处理加载错误
            loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError);
            loader.contentLoaderInfo.addEventListener(Event.COMPLETE, function(event:Event):void{
                callback( Bitmap( loader.content ).bitmapData );
            } );
        }
        
        /**
         * 加载错误
         * @param event
         * 
         */        
        protected static function onError(event:IOErrorEvent):void
        {
            trace(" urloader error....");

        }

使用方法

            protected function init(event:FlexEvent):void
            {
                LoaderHelper.loadXML( "mySpritesheet.xml", onXMLLoaded );
                LoaderHelper.loadImage( "mySpritesheet.png", onImageLoaded );
            }
            
            private function onXMLLoaded(xml:XML):void
            {
                trace( xml.toString() );
            }
            
            private function onImageLoaded(bd:BitmapData):void
            {
                var image:Image = new Image();
                image.source = new Bitmap( bd );
                addChild( image );
            }