ASP.NET Tutorial/Cookie/Introduction
Create a persistent cookie.
<source lang="csharp">
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server">
void Page_Load()
{
int counter = 0;
if (Request.Cookies["counter"] != null)
counter = Int32.Parse(Request.Cookies["counter"].Value);
counter++;
Response.Cookies["counter"].Value = counter.ToString();
Response.Cookies["counter"].Expires = DateTime.Now.AddYears(2);
lblCounter.Text = counter.ToString();
}
</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">
<title>Set Persistent Cookie</title>
</head> <body>
<form id="form1" runat="server">
You have visited this page
<asp:Label
id="lblCounter"
Runat="server" />
times!
</form>
</body> </html></source>
Creating a new cookie.
<source lang="csharp">
Be warned that cookie names are case sensitive.
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server">
protected void btnAdd_Click(object sender, EventArgs e)
{
Response.Cookies["message"].Value = txtCookieValue.Text;
}
</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">
<title>Set Cookie</title>
</head> <body>
<form id="form1" runat="server">
<asp:Label
id="lblCookieValue"
Text="Cookie Value:"
AssociatedControlID="txtCookieValue"
Runat="server" />
<asp:TextBox
id="txtCookieValue"
Runat="server" />
<asp:Button
id="btnAdd"
Text="Add Value"
OnClick="btnAdd_Click"
Runat="server" />
</form>
</body> </html></source>
Using Browser Cookies
<source lang="csharp">
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 You can store only string values when using a cookie. Two types of cookies: session cookies and persistent cookies. A session cookie exists only in memory. A persistent cookie can last for months or even years. A persistent cookie is stored permanently by the user"s browser on the user"s computer.</source>
