Uploadify上传丢失Session

问题说明

asp.net 项目中有一个上传图片的地方使用的 uploadify 上传插件，而且采用的 FLASH 版本，该功能有一阵子没使用过了，等现在要用的时候发现一个严重问题，提交上传后直接导致项目 Session 丢失，查看代码后发现调用 uploadify 后会创建一个新的 Session ，下面是解决办法。

前台 js 代码

$(function () {
            var auth = "<% = Request.Cookies[FormsAuthentication.FormsCookieName]==null ? string.Empty : Request.Cookies[FormsAuthentication.FormsCookieName].Value %>";
            var ASPSESSID = "<%= Session.SessionID %>";
            uploader = new AjaxUploaderBtn(document.getElementById("uploader")); 
            uploader.init({
                fileTypeExts: "*.gif; *.jpg; *.png; *.jpeg;",
                onSWFReady: function () {
                        $(uploader.btn).uploadify("disable", true);
                },
                onUploadStart: function (file) {
                    $(uploader.btn).uploadify("settings", "formData", { 'lang': "en", ASPSESSID: ASPSESSID, AUTHID: auth });
                },
                onUploadSuccess: function (file, data, response) {
                    var json = JSON.parse(data);                    
                    if (response && json.Success) {
                        console.log(json);
                    }
                    else if (false == json.Success) {
                        console.log(json.message);
                    }
                    else {
                        alert("Request error.");
                    }
                },
                onUploadError: function (file, errorCode, errorMsg, errorString) {
                    alert('The file ' + file.name + ' could not be uploaded: ' + errorString);
                }
            });
        });

AjaxUploaderBtn 是封装的一个 js 函数，这里的重点代码是：

声明两个变量

1
2

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

传递变量

在 formData 中传递这两个变量

1	$(uploader.btn).uploadify("settings", "formData", { ASPSESSID: ASPSESSID, AUTHID: auth });

后台处理

打开 Global.asax 文件

添加一个函数

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);
}

修改 Application_BeginRequest 方法

protected void Application_BeginRequest (object sender, EventArgs e)
{
    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 { }
}