flex:使用FileReference上传文件

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init()" width="1000" height="700" color="#25C1E2"> 
<mx:Script> 
<![CDATA[ 
private const defaultRequestUrl:String = "http://www.mysite.com/upload_ok.php";          
private var file : FileReference; 
private function init():void { 
Security.allowDomain("*"); 
file = new FileReference(); 
file.addEventListener(Event.SELECT, onFileSelect); 
file.addEventListener(ProgressEvent.PROGRESS, progressHandle); 
file.addEventListener(Event.COMPLETE, completeHandle); 
//file.addEventListener(Event.OPEN, openHandle); 
//file.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler); 
                    //file.addEventListener(Event.CANCEL, cancelHandler); 
                } 
                  
                private function onClickBrowserBtn() : void { 
                    file.browse(getTypeFilter()); 
                } 
                  
                private function getTypeFilter() : Array { 
                    var imagesFilter:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg;*.jpeg;*.gif;*.png"); 
                    //var docFilter:FileFilter = new FileFilter("Documents", "*.pdf;*.doc;*.txt"); 
                      
                    return [imagesFilter]; 
                } 
                  
                private function onFileSelect(event : Event) : void { 
                    uploadBtn.enabled = true; 
                    infoText.htmlText = "Name: "+file.name+" "+"Size: "+file.size+" "+
                        "Type: " + file.type + " " +   
                        "Date: " + file.creationDate; 
                } 
                  
                private function onClickUploadBtn() : void { 
                    var request : URLRequest = new URLRequest(defaultRequestUrl); 
                    request.data = "userId=123"; 
                    file.upload(request); 
                } 
                  
                private function progressHandle(event : ProgressEvent) : void { 
                    progressLabel.text = "complete " + event.bytesLoaded + " bytes"; 
                    var fileUploadPercent : uint = event.bytesLoaded / event.bytesTotal * 100; 
                    uploadProgressBar.setProgress(fileUploadPercent, 100); 
                    uploadProgressBar.label = "Complete " + fileUploadPercent + "%"; 
                } 
                  
                private function completeHandle(event : Event) : void { 
                    infoText.htmlText = "Upload " + file.name + " Complete!"; 
                    uploadBtn.enabled = false; 
                } 
            ]]>
        </mx:Script> 
          
        <mx:Button id="browserBtn" x="10" y="69" label="浏览" styleName="mylinkButton"   
            click="onClickBrowserBtn()"/> 
              
        <mx:Button id="uploadBtn" x="236" y="69" label="上传" enabled="false"   
            click="onClickUploadBtn()"/> 
              
        <mx:ProgressBar id="uploadProgressBar" x="10" y="33" width="291"   
            themeColor="#009dff" maximum="100" direction="right" mode="manual"/> 
              
        <mx:TextArea id="infoText" x="10" y="99" width="291" height="131"/> 
        <mx:Label id="progressLabel" x="10" y="10" width="291"/> 

   </mx:Application> 

//------------------------分析--------------------------------
1 需要被上传的文件被声明为FileReference类

2 文件上传进度监控：file.addEventListener(ProgressEvent.PROGRESS, progressHandle); 

3 具体上传代码：
var request : URLRequest = new URLRequest(defaultRequestUrl); 
request.data = "userId=123"; 
file.upload(request); 
注意：request.data属性设置为变量名和值组成的字符串，upload方法的参数为request

4 打开文件浏览窗口用：
file.browse(getTypeFilter()); 

5 注意FileFilter的用法，它直接作为FileReference类的成员函数browse的参数
var imagesFilter:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg;*.jpeg;*.gif;*.png"); 

6 注意进度条的用法：
private function progressHandle(event : ProgressEvent) : void { 
       progressLabel.text = "complete " + event.bytesLoaded + " bytes"; 
       var fileUploadPercent : uint = event.bytesLoaded / event.bytesTotal * 100; 
       uploadProgressBar.setProgress(fileUploadPercent, 100); 
       uploadProgressBar.label = "Complete " + fileUploadPercent + "%"; 
} 
计算当前进度：
event.bytesLoaded / event.bytesTotal 
设置当前进度：
uploadProgressBar.setProgress(fileUploadPercent, 100); 
显示当前进度：
<mx:ProgressBar id="uploadProgressBar" x="10" y="33" width="291"   
maximum="100" direction="right" mode="manual"/>

7、URLRequest的data属性可以与URLVariables类结合使用

1.  urlVars = new URLVariables();
2.                 urlVars.userID = 94103;
3.                 urlVars.fpVersion = flash.system.Capabilities.version;
4.  
5.                 urlReq = new URLRequest();
6.                 urlReq.method = URLRequestMethod.POST;
7.                 urlReq.data = urlVars;
8.                 urlReq.url = "http://localhost:8300/fileref/uploader.cfm";