[ActionScript3.0] 使用FileReference处理单个文件的上载

package
{
    import flash.display.SimpleButton;
    import flash.display.Sprite;
    import flash.errors.IllegalOperationError;
    import flash.errors.MemoryError;
    import flash.events.DataEvent;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.events.ProgressEvent;
    import flash.net.FileFilter;
    import flash.net.FileReference;
    import flash.net.URLRequest;
    import flash.net.URLRequestMethod;
    import flash.net.URLVariables;
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;
    /**
     * ...
     * @author Frost.Yen
     */
    public class UploadAS3 extends Sprite
    {
        private var _label:TextField; 
        private var _button:TextField;
        private var _fileRefer:FileReference; 
        private var _request:URLRequest = new URLRequest("http://localhost/yanzimen/");
        public function UploadAS3()
        {
            if(stage) init();
            else addEventListener(Event.ADDED_TO_STAGE,init);
        }
        private function init(e:Event = null):void
        {
            _label = new TextField(); 
            _label.text = "please select file"; 
            _label.autoSize = TextFieldAutoSize.LEFT;
            _label.background = true;
            _label.width = 300;
            _label.wordWrap = true;
            _label.backgroundColor = 0xffffff;
            _label.border = true;
            _button = new TextField();
            _button.text = "click here to select file";
            _button.autoSize = TextFieldAutoSize.LEFT; 
            _button.selectable = false;
            _button.background = true;
            _button.backgroundColor = 0xE29966;
            _button.border = true;
            this.addChild(_label); 
            this.addChild(_button); 
            _button.x = 310;
       
            _fileRefer = new FileReference();
            _button.addEventListener(MouseEvent.CLICK,toSelect);
            _fileRefer.addEventListener(Event.SELECT,onSelect);
            _fileRefer.addEventListener(Event.CANCEL,onCancel);
        }
        private function toSelect(e:MouseEvent):void
        {
            _fileRefer.browse(); //browse(typeFilter:Array=null) 使用 typeFilter 参数，可决定对话框显示哪些文件。
            _button.removeEventListener(MouseEvent.CLICK,toSelect); 
        }
        private function onProgress(e:ProgressEvent):void
        {
            _label.text = Number(Math.round(e.bytesLoaded / e.bytesTotal*100))+"%";
            //label.text = e.bytesLoaded+"/"+e.bytesTotal;
        }
        private function onComplete(e:Event):void
        {
            _fileRefer.removeEventListener(Event.COMPLETE,onComplete);
            _fileRefer.removeEventListener(ProgressEvent.PROGRESS,onProgress);
            _button.addEventListener(MouseEvent.CLICK,toUpload);
            _label.text = "load complete!";
            _button.text = "upload";
        }
        private function toUpload(e:MouseEvent):void{
            onUpLoad(_fileRefer);
        }
        private function onSelect(e:Event):void
        {
            trace("the name of the selected file:",(e.target as FileReference).name);
            _label.text = "file name:"+(e.target as FileReference).name;
            _fileRefer.addEventListener(Event.COMPLETE,onComplete);
            _fileRefer.addEventListener(ProgressEvent.PROGRESS,onProgress);
            _fileRefer.load();
        }
        private function onCancel(e:Event):void
        {
            trace("cancel to upload");
            _button.addEventListener(MouseEvent.CLICK,toSelect); 
        }
        /**
         * 调用FileReference的实例方法upload()实现文件上传
         * @param    file
         */
        private function onUpLoad(file:FileReference):void
        {
            _label.text = "file size"+Number(file.size/1024/1024).toFixed(2)+"M";
            var variables:URLVariables = new URLVariables();
            variables.fileName = file.name;
            _request.data = variables;
            _request.method = URLRequestMethod.POST;
            file.addEventListener(ProgressEvent.PROGRESS, progressHandler);
            file.addEventListener(Event.COMPLETE, completeHandler);
            file.addEventListener(DataEvent.UPLOAD_COMPLETE_DATA,completeDataHandler);
            try
            {
                file.upload(_request);
            } 
            catch(error:Error) 
            {
                trace(error.message);
            }
       
            function progressHandler(e:ProgressEvent):void
            {
                _label.text = "uploading "+Math.round(100 * e.bytesLoaded / e.bytesTotal) + "%";
            }
            function completeHandler(e:Event):void
            {
                var file:FileReference = FileReference(e.target);
                file.removeEventListener(ProgressEvent.PROGRESS, progressHandler);
                file.removeEventListener(Event.COMPLETE, completeHandler);
                _button.removeEventListener(MouseEvent.CLICK,toUpload);
                _button.addEventListener(MouseEvent.CLICK,toSelect);
                _label.text = "upload complete";
                _button.text = "click here to select file";
            }
            function completeDataHandler(e:DataEvent):void
            {
                var file:FileReference = FileReference(e.target);
                file.removeEventListener(DataEvent.UPLOAD_COMPLETE_DATA,completeHandler);
                trace(e.data);//上传成功后，从后台返回的数据
            }
        }
        /**
         * FileFilter 类用于表示在调用 FileReference.browse() 方法、FileReferenceList.browse() 方法或调用 File、FileReference 或 FileReferenceList 对象的 browse 方法时显示的文件浏览对话框中显示用户系统上的哪些文件。
         * @return
         */
        private function getImageTypeFilter():FileFilter {
            return new FileFilter("Images (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg;*.jpeg;*.gif;*.png");
        }
      
        private function getTextTypeFilter():FileFilter {
            return new FileFilter("Text Files (*.txt, *.rtf)", "*.txt;*.rtf");
        }
    }
}