如何压缩asp.net产生的viewstate

1. 在网站的app_code目录下面增加一个文件 ViewStateHelper.cs

using System.Linq;
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.Xml.Linq;

using System.IO;
using System.IO.Compression;

/// <summary>
///ViewStateHelper 的摘要说明
/// </summary>
public class ViewStateHelper
{
    public ViewStateHelper()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }
    public static byte[] Compress(byte[] data)
    {
        MemoryStream ms = new MemoryStream();
        GZipStream stream = new GZipStream(ms, CompressionMode.Compress);
        stream.Write(data, 0, data.Length);
        stream.Close();
        return ms.ToArray();
    }

    public static byte[] Decompress(byte[] data)
    {
        MemoryStream ms = new MemoryStream();
        ms.Write(data, 0, data.Length);
        ms.Position = 0;
        GZipStream stream = new GZipStream(ms, CompressionMode.Decompress);
        MemoryStream temp = new MemoryStream();
        byte[] buffer = new byte[1024];
        while (true)
        {
            int read = stream.Read(buffer, 0, buffer.Length);
            if (read <= 0)
            {
                break;
            }
            else
            {
                temp.Write(buffer, 0, buffer.Length);
            }
        }
        stream.Close();
        return temp.ToArray();
    }

}

2. 在需要压缩viewastate 的网页的后台文件里面增加代码

protected override void SavePageStateToPersistenceMedium(object state)
        {
            LosFormatter formatter = new LosFormatter();
            StringWriter writer = new StringWriter();
            formatter.Serialize(writer, state);
            string viewState = writer.ToString();
            byte[] data = Convert.FromBase64String(viewState);
            byte[] compressedData = ViewStateHelper.Compress(data);
            string str = Convert.ToBase64String(compressedData);
            ClientScript.RegisterHiddenField(" __MYVIEWSTATE ", str);
        }
        protected override object LoadPageStateFromPersistenceMedium()
        {
            string viewstate = Request.Form[" __MYVIEWSTATE "];
            byte[] data = Convert.FromBase64String(viewstate);
            byte[] uncompressedData =
           ViewStateHelper.Decompress(data);
            string str = Convert.ToBase64String(uncompressedData);
            LosFormatter formatter = new LosFormatter();
            return formatter.Deserialize(str);
        }