1、cookie类 CartCookie.cs

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using System.Text;
using Zip;

/// <summary>
///Serializer 的摘要说明
/// </summary>
public class CartCookie
{
    public CartCookie()
    { }

    /// <summary>
    /// 将对象写入Cookie
    /// </summary>
    public static void CartToCookie(object obj, string cookieName)
    {

        string str = SerializeObject(obj);
        str = Convert.ToBase64String(ZipClass.Compress(str));//压缩字符串
        HttpCookie hc = new HttpCookie(cookieName);
        hc.Value = HttpContext.Current.Server.UrlEncode(str);
        hc.Expires = DateTime.Now.AddDays(7);
        HttpContext.Current.Response.Cookies.Add(hc);

    }

    /// <summary>
    /// 将Cookie反序列化为
    /// </summary>
    public static object CookieToCart(string cookieName)
    {
        if (HttpContext.Current.Request.Cookies[cookieName] == null)
        {
            return null;
        }
        else
        {
            string str = HttpContext.Current.Request.Cookies[cookieName].Value;
            str = HttpContext.Current.Server.UrlDecode(str);
            str = Convert.ToBase64String(ZipClass.DeCompress(str));//解压缩字符串
            object obj = DeserializeObject(str);
            return obj;
        }
    }

    public static string SerializeObject(object o)
    {
        System.Runtime.Serialization.IFormatter obj = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();

        MemoryStream ms = new MemoryStream();
        obj.Serialize(ms, o);

        BinaryReader br = new BinaryReader(ms);
        ms.Position = 0;
        byte[] bs = br.ReadBytes((int)ms.Length);
        ms.Close();
        return Convert.ToBase64String(bs);

    }

    public static object DeserializeObject(string str)
    {
        System.Runtime.Serialization.IFormatter obj = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
        byte[] bs = Convert.FromBase64String(str);
        MemoryStream ms = new MemoryStream();
        ms.Write(bs, 0, bs.Length);
        ms.Position = 0;
        object o = obj.Deserialize(ms);
        ms.Close();

        return o;
    }

}

2、数据压缩类ZipClass.cs

using System;
using System.Web.UI;
using System.IO;
using ICSharpCode.SharpZipLib.Zip.Compression;

namespace Zip
{
    /**/
    /// <summary>
    /// PageClass 的摘要说明。
    /// </summary>
    public class ZipClass : System.Web.UI.Page
    {
        /**/
        /// <summary>
        /// 设定序列化后的字符串长度为多少后启用压缩
        /// </summary>
        private static Int32 LimitLength = 200;

        /**/
        /// <summary>
        /// 设定压缩比率，压缩比率越高性消耗也将增大
        /// </summary>
        private static Int32 ZipLevel = ICSharpCode.SharpZipLib.Zip.Compression.Deflater.BEST_COMPRESSION;

        /**/
        /// <summary>
        /// 重写保存页的所有视图状态信息
        /// </summary>
        /// <param name="pViewState">要在其中存储视图状态信息的对象</param>
        protected override void SavePageStateToPersistenceMedium(Object pViewState)
        {
            //实现一个用于将信息写入字符串的 TextWriter
            StringWriter mWriter = new StringWriter();

            //序列化 Web 窗体页的视图状态
            LosFormatter mFormat = new LosFormatter();

            //将有限对象序列化 (LOS) 格式化的对象转换为视图状态值
            mFormat.Serialize(mWriter, pViewState);

            //将序列化对象转成Base64字符串
            String vStateStr = mWriter.ToString();

            //设置是否启用了加密方式，默认情况下为不启用
            Boolean mUseZip = false;

            //判断序列化对象的字符串长度是否超出定义的长度界限
            if (vStateStr.Length > LimitLength)
            {
                //对于长度超出阶线的进行加密，同时将状态设为加密方式
                mUseZip = true;

                Byte[] pBytes = Compress(vStateStr);

                //将字节数组转换为Base64字符串
                vStateStr = System.Convert.ToBase64String(pBytes);
            }

            //注册在页面储存ViewState状态的隐藏文本框，并将内容写入这个文本框
            RegisterHiddenField("__MSPVSTATE", vStateStr);

            //注册在页面储存是否启用压缩状态的文本框，并将启用状态写入这个文本框
            RegisterHiddenField("__MSPVSTATE_ZIP", mUseZip.ToString().ToLower());
        }

        /**/
        /// <summary>
        /// 对字符串进行压缩
        /// </summary>
        /// <param name="pViewState">ViewState字符串</param>
        /// <returns>返回流的字节数组</returns>
        public static Byte[] Compress(String pViewState)
        {
            //将存储状态的Base64字串转换为字节数组
            Byte[] pBytes = System.Convert.FromBase64String(pViewState);

            //创建支持内存存储的流
            MemoryStream mMemory = new MemoryStream();

            Deflater mDeflater = new Deflater(ZipLevel);
            ICSharpCode.SharpZipLib.Zip.Compression.Streams.DeflaterOutputStream mStream = new ICSharpCode.SharpZipLib.Zip.Compression.Streams.DeflaterOutputStream(mMemory, mDeflater, 131072);

            mStream.Write(pBytes, 0, pBytes.Length);
            mStream.Close();

            return mMemory.ToArray();
        }

        /**/
        /// <summary>
        /// 重写将所有保存的视图状态信息加载到页面对象
        /// </summary>
        /// <returns>保存的视图状态</returns>
        protected override Object LoadPageStateFromPersistenceMedium()
        {
            //使用Request方法获取序列化的ViewState字符串
            String mViewState = this.Request.Form.Get("__MSPVSTATE");
            //使和Request方法获取当前的ViewState是否启用了压缩
            String mViewStateZip = this.Request.Form.Get("__MSPVSTATE_ZIP");

            Byte[] pBytes;

            if (mViewStateZip == "true")
            {
                pBytes = DeCompress(mViewState);
            }
            else
            {
                //将ViewState的Base64字符串转换成字节
                pBytes = System.Convert.FromBase64String(mViewState);
            }

            //序列化 Web 窗体页的视图状态
            LosFormatter mFormat = new LosFormatter();

            //将指定的视图状态值转换为有限对象序列化 (LOS) 格式化的对象
            return mFormat.Deserialize(System.Convert.ToBase64String(pBytes));
        }

        /**/
        /// <summary>
        /// 解压缩ViewState字符串
        /// </summary>
        /// <param name="pViewState">ViewState字符串</param>
        /// <returns>返回流的字节数组</returns>
        public static Byte[] DeCompress(String pViewState)
        {
            //将Base64字符串转换为字节数组
            Byte[] pBytes = System.Convert.FromBase64String(pViewState);

            ICSharpCode.SharpZipLib.Zip.Compression.Streams.InflaterInputStream mStream = new ICSharpCode.SharpZipLib.Zip.Compression.Streams.InflaterInputStream(new MemoryStream(pBytes));

            //创建支持内存存储的流
            MemoryStream mMemory = new MemoryStream();
            Int32 mSize;

            Byte[] mWriteData = new Byte[4096];

            while (true)
            {
                mSize = mStream.Read(mWriteData, 0, mWriteData.Length);
                if (mSize > 0)
                {
                    mMemory.Write(mWriteData, 0, mSize);
                }
                else
                {
                    break;
                }
            }

            mStream.Close();
            return mMemory.ToArray();
        }

    }
}