Track Your Viewstate : ViewState « Page Lifecycle « ASP.NET Tutorial

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" 
    Inherits="Default" Theme="Core35-Basic" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Track Your Viewstate</title>
</head>
<body>
    <form id="form1" runat="server">
    <div id="pageContent">
        <asp:Button ID="Button1" runat="server" Text="Post back..." OnClick="Button1_Click" />
        <br />
        <br />
    </div>
    </form>
</body>
</html>

File: Default.aspx.cs

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;


public partial class Default : System.Web.UI.Page
{
  protected void Page_PreInit(object sender, EventArgs e)
  {
    this.TraceEnabled = true;
  }

    protected void Page_Init(object sender, EventArgs e)
  {
    if (!IsPostBack)
    {
      this.ViewState["MyData"] = "Hello, world";
    }

    Trace.Warn("[MyData] now contains", (string) ViewState["MyData"]);
  }
  
    protected void Page_Load(object sender, EventArgs e)
  {
    Trace.Warn("[MyData] now contains", (string)ViewState["MyData"]);
  }

}

5.21.ViewState
	5.21.1.	Use ViewState to create a simple counter (C#)
	5.21.2.	Save string variable to ViewState
	5.21.3.	Convert.FromBase64String and view state encoding
	5.21.4.	Use ViewState to store random data
	5.21.5.	Visualize the current Base64-encoded contents of the view state
	5.21.6.	Track Your Viewstate