ViewState Compression ....

Compressing and Decompressing Data in Memory

The code below is really simple, and doesn't need further explanation:

using System.IO;

using System.IO.Compression;

public static class Compressor

{

    public static byte[] Compress(byte[] data)

    {

        MemoryStream output = new MemoryStream();

        GZipStream gzip = new GZipStream(output,

                          CompressionMode.Compress, true);

        gzip.Write(data, 0, data.Length);

        gzip.Close();

        return output.ToArray();

    }

    public static byte[] Decompress(byte[] data)

    {

        MemoryStream input = new MemoryStream();

        input.Write(data, 0, data.Length);

        input.Position = 0;

        GZipStream gzip = new GZipStream(input,

                          CompressionMode.Decompress, true);

        MemoryStream output = new MemoryStream();

        byte[] buff = new byte[64];

        int read = -1;

        read = gzip.Read(buff, 0, buff.Length);

        while (read > 0)

        {

            output.Write(buff, 0, read);

            read = gzip.Read(buff, 0, buff.Length);

        }

        gzip.Close();

        return output.ToArray();

    }

}

In your base page include these methods and you are done:

protected override object LoadPageStateFromPersistenceMedium()

    {

        string viewState = Request.Form["__VSTATE"];

        byte[] bytes = Convert.FromBase64String(viewState);

        bytes = Compressor.Decompress(bytes);

        LosFormatter formatter = new LosFormatter();

        return formatter.Deserialize(Convert.ToBase64String(bytes));

    }

    protected override void SavePageStateToPersistenceMedium(object viewState)

    {

        LosFormatter formatter = new LosFormatter();

        StringWriter writer = new StringWriter();

        formatter.Serialize(writer, viewState);

        string viewStateString = writer.ToString();

        byte[] bytes = Convert.FromBase64String(viewStateString);

        bytes = Compressor.Compress(bytes);

        ClientScript.RegisterHiddenField("__VSTATE", Convert.ToBase64String(bytes));

    }

Now view your aspx page in firefox Viewstate size addon will show your reduced size...