《ASP.NET 3.5揭秘》读书笔记
cookie 分为：会话cookie和持久化cookie两种。
会话cookie只存在于内存中；
持久化cookie可以存在几个月甚至几年，持久化cookie创建后，会被浏览器长久地保存在用户的电脑上。（如IE存在这个文件夹里：\Documents and Settings\[user]\Cookies）
创建会话cookie。
通过Response.Cookies集合添加cookie来创建新的cookie。
<%@ 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 runat="server"> <title>Set Cookie</title> </head> <body> <form id="form1" runat="server"> <div> <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"/> </div> </form> </body> </html>
创建持久cookie。
如果希望创建持久化cookies，则需要为cookie指定一个过期时间。如下面程序中Respo.Cookies["counter"].Expires = DataTime.Now.AddYears(2);
<%@ 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() { // Get current value of cookie int counter = 0; if (Request.Cookies["counter"] != null) { counter = Int32.Parse(Request.Cookies["counter"].Value); } // Increment counter counter++; // Add Peristent cookie to browser Response.Cookies["counter"].Value = counter.ToString(); Response.Cookies["counter"].Expires = DateTime.Now.AddYears(2); // Display value of counter cookie lblCounter.Text = counter.ToString(); } </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Set Persister Cookie</title> </head> <body> <form id="form1" runat="server"> <div> You have visited this page <asp:Label id="lblCounter" Runat = "server" /> times! </div> </form> </body> </html>