function upload() {             var options = {                 type: "POST",                            //当然这个是传送方式                 url: '../Include/Files.ashx',        //一般处理程序的路径                 success: function (msg) {        //返回的参数                     $("#server_img").attr("src", msg);            //回显图片。                 }             };             // 将options传给ajaxForm             $('#aspnetForm').ajaxSubmit(options);  }

 public void ProcessRequest(HttpContext context)     {         HttpFileCollection files = context.Request.Files;              // From中获取文件对象         if (files.Count > 0)         {              string path = "";                                                            //路径字符串             Random rnd = new Random();             for (int i = 0; i < files.Count; i++)             {                 HttpPostedFile file = files[i];                                        //得到文件对象                 if (file.ContentLength > 0)                 {                     string fileName = file.FileName;                     string extension = Path.GetExtension(fileName);                     int num = rnd.Next(5000, 10000);                            //文件名称                     path = "../../UserFiles/temp/" + num.ToString() + extension;                     file.SaveAs(System.Web.HttpContext.Current.Server.MapPath(path));        //保存文件。                 }             }             context.Response.Write(path);            //返回文件存储后的路径，用于回显。         }     }

    <img id="server_img" width="360px" style="border: 1px solid #ccc; padding: 2px;"   title="" alt="" />   //用于回显图片     <asp:FileUpload ID="Up_load" runat="server" onchange="upload()"  ontextchange="upload()"/>        //上传图片，自动的，两个事件是为了保证所有浏览器都兼容。