Studio711.com

I was recently working on a project which required a user to enter their member name on every page in order to access the web service it was tied to. Obviously this is very time consuming and not exactly pretty. In the old days, this could have been overcome by passing parameters in the URL. With ASP.NET, this can be accomplished much easier and much cleaner.

SessionState
Passing variables between pages is quite simple. The server keeps track of each user's session and the variables associated with that session. To add my own variables, I simply use this single line of code:

Session["member"] = txtMember.Text;

That line of code reads the text entered in the txtMember box and stores it in the Session variable with a key of "member". I can access the variable as easily as I created it. To set a text box to the current member, use this line of code:

txtMember.Text = Session["member"];

That's all there is to it. Simple, right? ASP.NET automatically differentiates between different concurrent users so you don't have to worry about it.

Cookies
Now let's say I want to store the member's name so that they are automatically logged on when they visit the site. This requires a cookie. It's a few more lines of code than the Session variable but not much more difficult.

To create the cookie:

HttpCookie cookie = new HttpCookie("MySite");
cookie.Values.Add("member",txtMember.Text);
cookie.Expires = DateTime.MaxValue; // Never Expires
Response.AppendCookie(cookie);

Here, the cookie name is MySite. A key of "member" is added with the value of the text box. Multiple values can be added to the same cookie. It's also possible to specify when the cookie expires. This example sets the cookie to never expire. To make the cookie expire in 7 days:

...
DateTime dt = DateTime.Now;
TimeSpan span = new TimeSpan(7,0,0,0);
cookie.Expires = dt.Add(span);
...

The cookie is now created and stored on the client's computer. To access the cookie and read values from it:

HttpCookie cookie = Request.Cookies["MySite"];
if (cookie != null)
    result = cookie.Values["member"];

Now you can read and write cookies as well as set session variables. The combination of these two skills allow you to create simple, powerful, and professional looking member pages.

This code was accepted as a tutorial on Devhood!

Disclaimer:
By installing this software, you assume complete responsibility for any damage that may occur to your system or your oldest child. I assume no liability. Besides, if you tried to sue me you wouldn't get much. May cause cancer in pregnant lab rats on rainy days in Arkansas. Violators will be persecuted. Do not pass Go, do not collect $200, go directly to jail. An apple a day keeps the doctor away. Caffeine-free (although I am probably not). Look both ways before crossing the road. Don't put that quarter in your mouth, you don't know where it's been. Do not use in areas of high radiation. Do not use while being chased by a rabid African tiger (a healthy one maybe, but not a rabid one). I am not responsible for any lost or stolen brain cells. And last, but not least, have fun!

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