Cookies In Asp.Net

Cookies is a small piece of information stored on the client machine. This file is located on client machines "C:\Document and Settings\Currently_Login user\Cookie" path.  Its is used to store user preference information like Username, Password,City and PhoneNo etc on client machines. We need to import namespace called  Systen.Web.HttpCookie before we use cookie. 
  
Type of Cookies?


Persist Cookie - A cookie has not have expired time Which is called as Persist Cookie


Non-Persist Cookie - A cookie has expired time Which is called as Non-Persist Cookie


How to create a cookie? 
  
Its really easy to create a cookie in the Asp.Net with help of Response object or HttpCookie 
  
Example 1: 
  
        HttpCookie userInfo = new HttpCookie("userInfo");
        userInfo["UserName"] = "Annathurai";
        userInfo["UserColor"] = "Black";
        userInfo.Expires.Add(new TimeSpan(0, 1, 0));
        Response.Cookies.Add(userInfo);



Example 2: 
  
        Response.Cookies["userName"].Value = "Annathurai";
        Response.Cookies["userColor"].Value = "Black";
                        
How to retrieve from cookie? 


Its easy way to retrieve cookie value form cookes by help of Request object. 
  
Example 1: 
  
        string User_Name = string.Empty;
        string User_Color = string.Empty;
        User_Name = Request.Cookies["userName"].Value;
        User_Color = Request.Cookies["userColor"].Value;


Example 2: 
  
        string User_name = string.Empty;
        string User_color = string.Empty;
        HttpCookie reqCookies = Request.Cookies["userInfo"];
        if (reqCookies != null)
        {
            User_name = reqCookies["UserName"].ToString();
            User_color = reqCookies["UserColor"].ToString();
        }
  
When we make request from client to web server, the web server process the request and give the lot of information with big pockets  which will have Header information, Metadata, cookies etc., Then repose object can do all the things with browser. 


Cookie's common property:


Domain => Which is used to associate cookies to domain.


Secure  => We can enable secure cookie to set true(HTTPs).


Value    => We can manipulate individual cookie.


Values  => We can manipulate cookies with key/value pair.


Expires => Which is used to set expire date for the cookies.


Advantages of Cookie:


Its clear text so user can able to read it.


We can store user preference information on the client machine.


Its easy way to maintain.


Fast accessing.


Disadvantages of Cookie


If user clear cookie information we can't get it back.


No security.


Each request will have cookie information with page.


How to clear the cookie information?


we can clear cookie information from client machine on cookie folder


To set expires to cookie object 
userInfo.Expires = DateTime.Now.AddHours(1); 
It will clear the cookie with one hour duration.