Managing State with ASP.NET and C#

Web Applications are disconnected in nature which means that there is no way for the browser to know who is using the application at present time. In classic Asp programming maintaining state was a headache for the developers. They had to write alot of code to maintain state. But Asp.net model provides easy state management. In this article we will see how we can persist state in multiple pages so the user is recognized by the browser.

Preserving State in Web Applications

There are number of ways that you can use to preserve the State of the Web Application. Here are some of the possible ways listed.

1) Using Cookies

2) Using Session States

3) Using Application States

4) Using HttpContext collection

5) Using ViewState

These are only some ways of storing the state of the user as well as the application. In this article we will see few of them in detail.

Using Cookies to maintain the state of the application

Cookies are created on the server side but saved on the client side. In the button click event of 'Cookies', write this code:

HttpCookie cName = new HttpCookie("Name");
cName.Value = txtName.Text;
Response.Cookies.Add(cName);
Response.Redirect("WebForm5.aspx");

First, we create a cookie named "cName". Since one cookie instance can hold many values, we tell the compiler that this cookie will hold "Name" value. We assign to it the value of the TextBox and finally add it in the Response stream, and sent it to the other page using Response.Redirect method.

Cookies can also have expiration time which means they can expire at some specified time or you can also set the sliding time which means that will expire is that cookies is not being used.

Using Cookieless Sessions in Asp.net

For all those users who have configured not to accept cookies they can use cookie less sessions. Here is a simple syntax of using the cookieless sessions.

sessionState
mode="Off"
stateConnectionString=
"tcpip=127.0.0.1:42424"
sqlConnectionString="data source=(local);
Integrated Security=SSPI"
cookieless="true"
timeout="20"

The only downside of using the cookieless sessions is that you cannot use the absolute urls and must code each link manually.

Using Session Variables to store the state of the application

Sessions are created as soon as the first response is being sent from the client to the server, and session ends when the user closes his browser window or some abnormal operation takes place. Here is how you can use session variables for transferring values. Below you can see a Session is created for the user and "Name" is the key, also known as the Session key, which is assigned the TextBox value.

// Session Created
Session["Name"] = txtName.Text;
Response.Redirect("WebForm5.aspx");

// The code below shows how to get the session value.
// This code must be placed in other page.
if(Session["Name"] != null)
Label3.Text = Session["Name"].ToString();

We can also store collections in the Session variables. These collections can be ArrayList or HashTables. Later you can use the casting to retrieve those collections.