Compress the viewstate Information

Introduction

This tip discusses how to compress the viewstate information of your aspx page if needed.

Using the Code

1. Create the following Compressor class in your project.
2. Override the two methods - LoadPageStateFromPersistenceMedium() and SavePageStateToPersistenceMedium(object viewState) in your cs file.
   

   // Create the following class file in your project which is used 
   // to compress and decompress the viewstate info  
   
   using System;
   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();
       }
   
   }

   // Override the two Methods 
      
      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);
           ScriptManager.RegisterHiddenField(updPnl, "__VSTATE", Convert.ToBase64String(bytes));
       }