今天在使用uploadify时发现session会发生丢失的情况，经过一番研究发现，其丢失并不是真正的丢失，而是在使用Flash上传控件的时候使用的session机制和asp.net中的不相同。为解决这个问题使用两种方案，下面进行介绍

第一种：修改Gobal

前台aspx页面：

$("#uploadify").uploadify({ 'uploader': '/LZKS/Handler/BigFileUpLoadHandler.ashx', 'swf': '/LZKS/Scripts/uploadify/uploadify.swf', 'cancelImage': '/LZKS/Scripts/uploadify/cancel.png', 'queueID': 'fileQueue', //'auto': false, 'multi': true, 'buttonText': '文件上传', 'formData': { 'ASPSESSID': ASPSESSID, 'AUTHID': auth }, 'onSelect': function (file) { $('#uploadify').uploadifySettings('formData', { 'ASPSESSID': ASPSESSID, 'AUTHID': auth }); alert(formDate); }, 'onComplete': function (file, data, response) { }, 'onQueueComplete': function () { alert("上传完成！"); $('#fileQueue').attr('style', 'visibility :hidden'); }, 'onSelectError': function (file, errorCode, errorMsg) { $('#fileQueue').attr('style', 'visibility :hidden'); }, 'onUploadStart': function (file) { $('#fileQueue').attr('style', 'top:200px;left:400px;width:400px;height :400px;visibility :visible'); } }); });

接着修改Gobal中的代码：

protected void Application_BeginRequest(object sender, EventArgs e) { /* we guess at this point session is not already retrieved by application so we recreate cookie with the session id... */ try { string session_param_name = "ASPSESSID"; string session_cookie_name = "ASP.NET_SessionId"; if (HttpContext.Current.Request.Form[session_param_name] != null) { UpdateCookie(session_cookie_name, HttpContext.Current.Request.Form[session_param_name]); } else if (HttpContext.Current.Request.QueryString[session_param_name] != null) { UpdateCookie(session_cookie_name, HttpContext.Current.Request.QueryString[session_param_name]); } } catch { } try { string auth_param_name = "AUTHID"; string auth_cookie_name = FormsAuthentication.FormsCookieName; if (HttpContext.Current.Request.Form[auth_param_name] != null) { UpdateCookie(auth_cookie_name, HttpContext.Current.Request.Form[auth_param_name]); } else if (HttpContext.Current.Request.QueryString[auth_param_name] != null) { UpdateCookie(auth_cookie_name, HttpContext.Current.Request.QueryString[auth_param_name]); } } catch { } } private void UpdateCookie(string cookie_name, string cookie_value) { HttpCookie cookie = HttpContext.Current.Request.Cookies.Get(cookie_name); if (null == cookie) { cookie = new HttpCookie(cookie_name); } cookie.Value = cookie_value; HttpContext.Current.Request.Cookies.Set(cookie); }

在JS加载前面定义下面两个变量

var auth = "<% = Request.Cookies[FormsAuthentication.FormsCookieName]==null ? string.Empty : Request.Cookies[FormsAuthentication.FormsCookieName].Value %>"; var ASPSESSID = "<%= Session.SessionID %>";

Handler文件代码如下：

public class BigFileUpLoadHandler : IHttpHandler, IRequiresSessionState { DALFile Fdal = new DALFile(); public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; VideoUpLoad(context, CLSOFT.Web.LZKS.Edu.Globe.filename); } public void VideoUpLoad(HttpContext context, string fileFolderName) { context.Response.Charset = "utf-8"; string aaaaaaa=context.Request.QueryString["sessionid"]; HttpPostedFile file = context.Request.Files["Filedata"]; string uploadPath = HttpContext.Current.Server.MapPath(UploadFileCommon.CreateDir(fileFolderName)); if (file != null) { if (!Directory.Exists(uploadPath)) { Directory.CreateDirectory(uploadPath); } Model.ModelFile model = new Model.ModelFile(); model.File_ID = Guid.NewGuid().ToString(); model.File_Name = file.FileName; model.File_Path = UploadFileCommon.CreateDir(fileFolderName); model.File_Size = file.ContentLength; model.File_Extension = file.FileName.Substring(file.FileName.LastIndexOf('.') + 1); model.File_Date = DateTime.Now; model.File_CurrentMan = CLSOFT.Web.LZKS.Edu.Globe.name; file.SaveAs(uploadPath + model.File_Name); List<Model.ModelFile> list = null; if (context.Session["File"] == null) { list = new List<Model.ModelFile>(); } else { list = context.Session["File"] as List<Model.ModelFile>; } list.Add(model); context.Session.Add("File", list); } else { context.Response.Write("0"); } }

这段代码的功能是将多文件的信息存到context.Session["File"] as List<Model.ModelFileModel.ModelFile>为文件信息类实现批量上传的信息给Session

第二种方案：直接向后台传递session值

Ext.onReady(function () { Ext.QuickTips.init(); <%--JQuery装载函数--%> $("#uploadify").uploadify({ 'uploader': '../Uploadify-v2.1.4/uploadify.swf',//上传swf相对路径 'script': '../Service/FileUploadHelper.ashx',//后台上传处理呈现 'cancelImg': '../Uploadify-v2.1.4/cancel.png',//取消上传按钮相对路径 'checkExisting':true,//服务端重复文件检测 'folder': '../UploadFile/',//上传目录 'fileExt':'*.jpg;*.png;*.gif;*.bmp',//允许上传的文件格式 'fileDesc':'jpg、png、gif、bmp',//文件选择时显示的提示 'queueID': 'fileQueue',//上传容器 'auto': false, 'multi': false,//只允许单文件上传 'buttonText':'Choose File', 'scriptData': { 'name': '', 'type': '','length':'' },//在加载时此处是null //'onInit':function(){alert("1");},//初始化工作，在Extjs的嵌套中最先触发的函数 //选择一个文件后触发 'onSelect': function(event, queueID, fileObj) { // alert("唯一标识:" + queueID + "rn" + // "文件名：" + fileObj.name + "rn" + // "文件大小：" + fileObj.size + "rn" + // "创建时间：" + fileObj.creationDate + "rn" + // "最后修改时间：" + fileObj.modificationDate + "rn" + // "文件类型：" + fileObj.type); $("#uploadify").uploadifySettings("scriptData", { "length": fileObj.size}); //动态更新配(执行此处时可获得值) }, //上传单个文件接收后触发 'onComplete': function (event, queueID, fileObj, response, data) { var value = response; if(value==1){ Ext.Msg.alert("提示","上传成功"); } else if(value==0){ Ext.Msg.alert("提示","请选择上传文件"); } else if(value==-1){ Ext.Msg.alert("提示","已存在该文件"); } } }); <%-- jQuery装载函数结束--%>

动态的传递参数，并判断是否合法

//动态加载 function loadFileType(){ //检测 var medianame=Ext.getCmp("eName").getValue(); if(medianame.trim()==""){ Ext.Msg.alert("提示","媒体名称不能为空"); return; } var filetype=Ext.getCmp("eType").getValue(); if(filetype=="" || filetype<0){ Ext.Msg.alert("提示","请选择媒体类型"); return; } //动态更新配(执行此处时可获得值) $("#uploadify").uploadifySettings("scriptData", { "name": medianame,"type":filetype,"sessionuserid":<%=session_userid %> }); //上传开始 $('#uploadify').uploadifyUpload(); }

<%=session_userid %>是取后台的一个变量，该变量在加载页面的时候获得了session值。当然也可以在前台直接获得session值。

后台处理程序：

public class FileUploadHelper : IRequiresSessionState, IHttpHandler { int nCurrentUserID = -1; public void ProcessRequest(HttpContext context) { try { nCurrentUserID = WebUtil.GetCurrentUserID();//该处的session值得不到 } catch (Exception) { } context.Response.ContentType = "text/plain"; context.Response.Charset = "utf-8"; string strFilename = string.Empty; int nFiletype = 0; float fFilelength = 0; string strFileExt = string.Empty; string strFilePath = string.Empty; if (context.Request["sessionuserid"] != null) { nCurrentUserID = Convert.ToInt32(context.Request["sessionuserid"].ToString()); } if (context.Request["name"] != null)//获得文件名(动态参数) { strFilename = context.Request["name"].ToString(); } if (context.Request["type"] != null)//获得文件类型（动态参数） { nFiletype = Convert.ToInt32(context.Request["type"].ToString()); } if (context.Request["length"] != null)//获得文件长度（动态参数） { int nEmptFileLength = Convert.ToInt32(context.Request["length"].ToString()); fFilelength = (float)nEmptFileLength / 1024; } if (context.Request["Filename"] != null)//获得文件名（系统自带） { string filename = context.Request["Filename"].ToString(); strFileExt = Path.GetExtension(filename).ToLower();//获得后缀名 } HttpPostedFile file = context.Request.Files["Filedata"]; string uploadPath = HttpContext.Current.Server.MapPath(@context.Request["folder"]); //根据当前日期创建一个文件夹 string dirName = System.DateTime.Now.ToString("yyyyMMdd"); uploadPath += dirName; string tmpRootDir = context.Server.MapPath(System.Web.HttpContext.Current.Request.ApplicationPath.ToString());//获取程序根目录 if (file != null) { //判断目录是否存在 if (!Directory.Exists(uploadPath)) { Directory.CreateDirectory(uploadPath); } //判断文件是否存在 strFilePath = uploadPath + "" + strFilename + strFileExt; if (!File.Exists(strFilePath)) { //写数据库成功保存文件 Media model = new Media(); int newMediaID = -1; model.media_type = nFiletype; model.media_name = strFilename + strFileExt; model.file_path = strFilePath.Replace(tmpRootDir, "");//保存相对目录 model.file_length = fFilelength; newMediaID = MediaBLL.AddMadia(model, nCurrentUserID); if (newMediaID > -1)//数据库写入成功 { //保存文件 file.SaveAs(strFilePath); //下面这句代码缺少的话，上传成功后上传队列的显示不会自动消失 context.Response.Write("1"); } } else { context.Response.Write("-1"); } } else { context.Response.Write("0"); } }

这样就可以解决该问题了。

希望这两种方法都能帮助大家顺利解决session丢失问题，谢谢大家的阅读。