/// <summary>
/// 上传文件到远程服务器
/// </summary>
/// <param name="fileBytes">文件流</param>
/// <param name="fileName">文件名</param>
/// <returns>字符串</returns>
[WebMethod(Description = "上传文件到远程服务器.")]
public string UploadFile(byte[] fileBytes, string fileName)
{
try
{
MemoryStream memoryStream = new MemoryStream(fileBytes); //1.定义并实例化一个内存流，以存放提交上来的字节数组。
FileStream fileUpload = new FileStream(Server.MapPath(".") + "\\" + fileName, FileMode.Create); ///2.定义实际文件对象，保存上载的文件。
memoryStream.WriteTo(fileUpload); ///3.把内存流里的数据写入物理文件
memoryStream.Close();
fileUpload.Close();
fileUpload = null;
memoryStream = null;
return "文件已经上传成功";
}
catch (Exception ex)
{
return ex.Message;
}
}

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" creationComplete="application1_creationCompleteHandler(event)">
<fx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.events.FlexEvent;
import mx.graphics.codec.JPEGEncoder;
import mx.rpc.events.FaultEvent;
import mx.rpc.events.ResultEvent;

protected function application1_creationCompleteHandler(event:FlexEvent):void
{
var width :int = imgID.width;
var height :int = imgID.height;
var bitmapData:BitmapData =new BitmapData(width,height);
bitmapData.draw(imgID);

var byteArr:ByteArray = bitmapData.getPixels(new Rectangle(0,0,width,height));
var byteArr123:ByteArray =new JPEGEncoder().encodeByteArray(byteArr,width,height);

webService.UploadFile(byteArr123,"123.png");
}

protected function webService_faultHandler(event:FaultEvent):void
{
Alert.show(event.fault.toString());
}

protected function webService_successHandler(event:ResultEvent):void
{
Alert.show(event.result.toString());
}

]]>
</fx:Script>
<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
<s:WebService id="webService" wsdl="http://10.19.1.48/upImg/Service1.asmx?WSDL" fault="webService_faultHandler(event)">
<s:operation name="UploadFile" result="webService_successHandler(event)"></s:operation>
</s:WebService>
</fx:Declarations>
<mx:Image id="imgID" x="186" y="103" width="583" height="397" source="file:/G:/360云盘/照片/2013Beijing MapOfSubway.jpg"/>
</s:Application>