因公司项目需求，在客户端需要用户能够上传图片，为此我又写了一遍这个flash上传的小玩意，其实这个东东我已经写了好几个，但每次写时隔许久，每次写有要回忆（我的记性不好，所以总是记不住细节，好在原理还是忘不了，写写改改就出来了），现在发一遍，大家能用上的就拿去吧。

package  {
   import com.adobe.serialization.json.JSON; import com.flash.external.Delegate; import com.flash.uploader.utils.Base64; import com.flash.uploader.utils.JPEGEncoder; import flash.display.MovieClip; import flash.net.FileReference; import flash.display.Loader; import fl.controls.Button; import flash.text.TextField; import flash.text.TextFormat; import flash.events.MouseEvent; import flash.display.Sprite; import flash.events.Event; import flash.events.ProgressEvent; import flash.net.FileFilter; import flash.net.URLRequest; import flash.display.DisplayObject; import flash.net.URLLoader; import flash.net.URLVariables; import flash.net.URLRequestMethod; import flash.events.IOErrorEvent; import flash.events.SecurityErrorEvent; import flash.external.ExternalInterface; import flash.system.Security;     [SWF(width="216", height="230", frameRate="24", backgroundColor="#FFFFFF")] public class Main extends MovieClip {
   private const UPLOAD_IMAGE_URL:String = "后台接口"; private const MAX_FILE_SIZE_IN_KB:int = 2048; private const BOX_WIDTH:uint = 216; private const BOX_HEIGHT:uint = 205; private var invisible:Sprite; private var _label:TextField; private var _format:TextFormat; private var onLoadBtn:Button; private var _file:FileReference; private var _filter:FileFilter; private var _loader:Loader; private var _urlRequest:URLRequest; private var _urlData:URLVariables; private var _urlLoader:URLLoader; private var _result:Object; private var fileSize:Number; public function Main() {
   super();             Security.allowDomain("xxx.com"); //label;             _label = createLabel('Please load your image, press here',25,50,160,200)             this.addChild(_label); //invisible btn             invisible = new Sprite();             invisible.graphics.beginFill(0x000000,.3);             invisible.graphics.drawRect(1,1,BOX_WIDTH,BOX_HEIGHT);             invisible.graphics.endFill();             this.addChild(invisible);             invisible.addEventListener(MouseEvent.CLICK, clickSelect); //onLoadBtn             onLoadBtn = createBtn('start uploding',2,207,100,20);             this.addChild(onLoadBtn);             onLoadBtn.enabled = false; //_filter;             _filter = new FileFilter("Support All Images:(*.jpeg,*.jpg,*.gif,*.png)","*.jpeg;*.jpg;*.gif;*.png");         } private function clickSelect(event:MouseEvent):void{
               _file = new FileReference();             _file.addEventListener(Event.SELECT, onSelect);             _file.browse([_filter]);             } private function onSelect(event:Event):void{
               trace('select');             _file.removeEventListener(Event.SELECT, onSelect);             _file.load();             _file.addEventListener(ProgressEvent.PROGRESS, onProgress);             _file.addEventListener(Event.COMPLETE, onLoadFinish);             } private function onLoadFinish(event:Event):void{
               _file.removeEventListener(Event.COMPLETE, onLoadFinish);             _loader = new Loader();             _loader.loadBytes(_file.data);             _loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadComplete);             } private function loadComplete(event:Event):void{
               _loader.contentLoaderInfo.removeEventListener(Event.COMPLETE, loadComplete); /* check file size */             fileSize = Math.round(_file.size / 1024); if(fileSize > MAX_FILE_SIZE_IN_KB){
                   alertHandler("Your file must be under " +                              MAX_FILE_SIZE_IN_KB / 1024 +                              "MB and in one of the following formats: *.JPEG,*.JPG,*.GIF,*.PNG");                 } else{
   //for better display img in a proper size;                 trace(_loader.content.width+'||'+_loader.content.height); if(_loader.content.width>BOX_WIDTH||_loader.content.height>BOX_HEIGHT){
   if(_loader.content.width<_loader.content.height){
                           _loader.content.width  = _loader.content.width *(BOX_HEIGHT/_loader.content.height);                         _loader.content.height = BOX_HEIGHT;                        } else if(_loader.content.width>_loader.content.height){
                           trace("width xiaoyu height")                         _loader.content.height  = _loader.content.height *(BOX_WIDTH/_loader.content.width);                         _loader.content.width = BOX_WIDTH;                     }                 } //center position image;             var varX:int = (BOX_WIDTH - _loader.content.width)/2; var varY:int = (BOX_HEIGHT - _loader.content.height)/2;             _loader.x = varX;             _loader.y = varY; //empty files             makeHoldEmpty(invisible);             invisible.addChild(_loader);                 _label.visible = false;                 onLoadBtn.enabled = true;                 onLoadBtn.addEventListener(MouseEvent.CLICK, startUpload);                 }             trace('name:'+_file.name+'\rtyep:'+_file.type+'\rcreator:'+_file.creator+'\rsize:'+_file.size);             } private function startUpload(event:MouseEvent):void{
               onLoadBtn.removeEventListener(MouseEvent.CLICK, startUpload);             _urlRequest = new URLRequest(UPLOAD_IMAGE_URL);             _urlRequest.method = URLRequestMethod.POST;             _urlData = new URLVariables;             _urlData.base64image = Base64.encode(_file.data);             _urlRequest.data = _urlData;             _urlLoader = new URLLoader()             _urlLoader.addEventListener(Event.COMPLETE, uploadComplete);             _urlLoader.addEventListener(IOErrorEvent.IO_ERROR, errorHandler);             _urlLoader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, errorHandler); try{
                   _urlLoader.load(_urlRequest)                 } catch(event){
                   errorHandler(null);                 }             trace('startUpload');             } private function uploadComplete(event:Event):void{
               _urlLoader.removeEventListener(Event.COMPLETE, uploadComplete);             _result = JSON.decode(event.currentTarget.data); if (ExternalInterface.available)             {
                   ExternalInterface.call("uploadFileCallback", _result);//here you can pass some parameters for debuging in browser.             }             } //error Handler;         private function errorHandler(event:Event){
   if (event.currentTarget.hasEventListener(IOErrorEvent.IO_ERROR))                 event.currentTarget.removeEventListener(IOErrorEvent.IO_ERROR, errorHandler); if (event.currentTarget.hasEventListener(SecurityErrorEvent.SECURITY_ERROR))                 event.currentTarget.removeEventListener(SecurityErrorEvent.SECURITY_ERROR, errorHandler); if (ExternalInterface.available)             {
   //ExternalInterface.call("uploadFileCallback",{success:false,message:null});             }             } private function onProgress(event:ProgressEvent){
   //具体你想加progress你就自己加吧;             } private function alertHandler(value):void         {
               Delegate.instance().jsAlert(value);         } //create label         private function createLabel(context:String,posx:int,posy:int,width:int=200,height:int=200):TextField{
   var _label:TextField = new TextField();             _label.text = context;             _format = new TextFormat('Arial',14,0x999999);             _label.wordWrap = true;             _label.setTextFormat(_format);             _label.x = posx;             _label.y = posy;             _label.width = width;             _label.height = height; return _label;             } //create label         private function createBtn(label:String,posx:int,posy:int,w:int = 50, h:int = 10):Button{
   var btn:Button = new Button();             btn.label = label;             btn.width = w;             btn.height = h;             btn.x = posx;             btn.y = posy; return btn;             } //check number for uploaded img;         private function makeHoldEmpty(target:Sprite):void{
   //remove all history children;             var numChild:int = target.numChildren; for(var i:int = 0; i