Session的使用

我想在ashx.cs中或者在class.cs中使用session，但是发现总是出现

“未将引用设置到实例的错误”

最后发现IHttpHandler,IRequiresSessionState 并不能对session进行修改

最后加了这些才可以，实现了对session的读取与修改。

最好把session和cookie方法封装成类

CookieHelper：

/*
 源码己托管:http://git.oschina.net/kuiyu/dotnetcodes
 */

using System;
using System.Web;

namespace DotNet.Utilities
{
    public class CookieHelper
    {
        /// <summary>
        /// 清除指定Cookie
        /// </summary>
        /// <param name="cookiename">cookiename</param>
        public static void ClearCookie(string cookiename)
        {
            HttpCookie cookie = HttpContext.Current.Request.Cookies[cookiename];
            if (cookie != null)
            {
                cookie.Expires = DateTime.Now.AddYears(-3);
                HttpContext.Current.Response.Cookies.Add(cookie);
            }
        }
        /// <summary>
        /// 获取指定Cookie值
        /// </summary>
        /// <param name="cookiename">cookiename</param>
        /// <returns></returns>
        public static string GetCookieValue(string cookiename)
        {
            HttpCookie cookie = HttpContext.Current.Request.Cookies[cookiename];
            string str = string.Empty;
            if (cookie != null)
            {
                str =HttpUtility.UrlDecode(cookie.Value);
            }
            return str;
        }
        /// <summary>
        /// 添加一个Cookie（24小时过期）
        /// </summary>
        /// <param name="cookiename"></param>
        /// <param name="cookievalue"></param>
        public static void SetCookie(string cookiename, string cookievalue)
        {
            SetCookie(cookiename, cookievalue, DateTime.Now.AddDays(1.0));
        }
        /// <summary>
        /// 添加一个Cookie
        /// </summary>
        /// <param name="cookiename">cookie名</param>
        /// <param name="cookievalue">cookie值</param>
        /// <param name="expires">过期时间 DateTime</param>
        public static void SetCookie(string cookiename, string cookievalue, DateTime expires)
        {
            HttpCookie cookie = new HttpCookie(cookiename)
            {
                Value = cookievalue,
                Expires = expires
            };
            HttpContext.Current.Response.Cookies.Add(cookie);
        }
    }
}

SessionHelper：

/*
 源码己托管:http://git.oschina.net/kuiyu/dotnetcodes
 */
using System.Web;

namespace DotNet.Utilities
{
    public static class SessionHelper2
    {
        /// <summary>
        /// 添加Session，调动有效期为20分钟
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <param name="strValue">Session值</param>
        public static void Add(string strSessionName, string strValue)
        {
            HttpContext.Current.Session[strSessionName] = strValue;
            HttpContext.Current.Session.Timeout = 20;
        }

        /// <summary>
        /// 添加Session，调动有效期为20分钟
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <param name="strValues">Session值数组</param>
        public static void Adds(string strSessionName, string[] strValues)
        {
            HttpContext.Current.Session[strSessionName] = strValues;
            HttpContext.Current.Session.Timeout = 20;
        }

        /// <summary>
        /// 添加Session
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <param name="strValue">Session值</param>
        /// <param name="iExpires">调动有效期（分钟）</param>
        public static void Add(string strSessionName, string strValue, int iExpires)
        {
            HttpContext.Current.Session[strSessionName] = strValue;
            HttpContext.Current.Session.Timeout = iExpires;
        }

        /// <summary>
        /// 添加Session
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <param name="strValues">Session值数组</param>
        /// <param name="iExpires">调动有效期（分钟）</param>
        public static void Adds(string strSessionName, string[] strValues, int iExpires)
        {
            HttpContext.Current.Session[strSessionName] = strValues;
            HttpContext.Current.Session.Timeout = iExpires;
        }

        /// <summary>
        /// 读取某个Session对象值
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <returns>Session对象值</returns>
        public static string Get(string strSessionName)
        {
            if (HttpContext.Current.Session[strSessionName] == null)
            {
                return null;
            }
            else
            {
                return HttpContext.Current.Session[strSessionName].ToString();
            }
        }

        /// <summary>
        /// 读取某个Session对象值数组
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <returns>Session对象值数组</returns>
        public static string[] Gets(string strSessionName)
        {
            if (HttpContext.Current.Session[strSessionName] == null)
            {
                return null;
            }
            else
            {
                return (string[])HttpContext.Current.Session[strSessionName];
            }
        }

        /// <summary>
        /// 删除某个Session对象
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        public static void Del(string strSessionName)
        {
            HttpContext.Current.Session[strSessionName] = null;
        }
    }
}