A cookie is a small amount of data that server creates on the client. When a web server creates a cookie, an additional HTTP header is sent to the browser when a page is served to the browser. The HTTP header looks like this:
Set-Cookie:
message=Hello. After a cookie has been created on a browser, whenever the browser requests a page from the same application in the future, the browser sends a header that looks like this:
Cookie: message=Hello
Cookie is little bit of text information. You can store only string values when using a cookie. There are two types of cookies:
- Session cookies
- Persistent cookies.
A session cookie exists only in memory. If a user closes the web browser, the session cookie delete permanently.
A persistent cookie, on the other hand, can available for months or even years. When you create a persistent cookie, the cookie is stored permanently by the user’s browser on the user’s computer.
Creating cookie
protected void btnAdd_Click(object sender, EventArgs e)
{
Response.Cookies[“message”].Value = txtMsgCookie.Text;
}
// Here txtMsgCookie is the ID of TextBox.
// cookie names are case sensitive. Cookie named message is different from setting a cookie named Message.
The above example creates a session cookie. The cookie disappears when you close your web browser. If you want to create a persistent cookie, then you need to specify an expiration date for the cookie.
Response.Cookies[“message”].Expires = DateTime.Now.AddYears(1);
Reading Cookies
void Page_Load()
{
if (Request.Cookies[“message”] != null)
lblCookieValue.Text = Request.Cookies[“message”].Value;
}
// Here lblCookieValue is the ID of Label Control.
