与session、applocation不同的是cookie是将数据存放于客户端的磁盘上，但cookie中只能含有少量的信息，通常不超过4096个字节。
protected void Page_Load(object sender, EventArgs e) { HttpCookie readcookie = Request.Cookies["user"]; if (readcookie != null) { Textbox1.Text = readcookie.Value; } } protected void Button1_Click(object sender, EventArgs e) { HttpCookie cookie = new HttpCookie("user"); DateTime dt = DateTime.Now; TimeSpan ts = new TimeSpan(0, 0, 6, 0); cookie.Expires = dt.Add(ts); cookie.Value = Textbox1.Text; Response.AppendCookie(cookie); }