Cookie (HttpCookie的实例)提供了一种在 Web 应用程序中存储用户特定信息的方法。例如，当用户访问您的站点时，您可以使用 Cookie 存储用户首选项或其他信息。当该用户再次访问您的网站时，应用程序便可以检索以前存储的信息。

C#.net部分

创建Cookie方法 (1)
Response.Cookies["userName"].Value = “admin";
Response.Cookies[“userName”].Expires = DateTime.Now.AddDays(1);
//如果不设置失效时间,Cookie信息不会写到用户硬盘,浏览器关闭将会丢弃。

创建Cookie方法 (2)
HttpCookie aCookie = new HttpCookie(“lastVisit”); //上一次访问时间
aCookie.Value = DateTime.Now.ToString();
aCookie.Expires = DateTime.Now.AddDays(1);
Response.Cookies.Add(aCookie);

访问Cookie方法(1)
if(Request.Cookies["userName"] != null)
Label1.Text = Server.HtmlEncode(Request.Cookies["userName"].Value);访问Cookie方法(2)
if(Request.Cookies["userName"] != null)
{
HttpCookie aCookie = Request.Cookies["userName"];
Label1.Text = Server.HtmlEncode(aCookie.Value);
}

创建多值Cookie方法 (1)
Response.Cookies["userInfo"]["userName"] = “admin";
Response.Cookies["userInfo"]["lastVisit"] = DateTime.Now.ToString();
Response.Cookies["userInfo"].Expires = DateTime.Now.AddDays(1);

创建多值Cookie方法 (2)
HttpCookie aCookie = new HttpCookie("userInfo");
aCookie.Values["userName"] = “admin";
aCookie.Values["lastVisit"] = DateTime.Now.ToString();
aCookie.Expires = DateTime.Now.AddDays(1);
Response.Cookies.Add(aCookie);

读取多值Cookie

HttpCookie aCookie = Request.Cookies["userInfo"];
string userName=aCookie.Values[“userName”];
string lastVisit=aCookie.Values[“lastVisit”];

vb.net部分

创建Cookie方法 (1)
Response.Cookies("userName").Value = “admin"
Response.Cookies(“userName”).Expires = DateTime.Now.AddDays(1)
'如果不设置失效时间,Cookie信息不会写到用户硬盘,浏览器关闭将会丢弃。
 
 
创建Cookie方法 (2)
Dim aCookie As HttpCookie =  New HttpCookie(“lastVisit”)  '上一次访问时间
aCookie.Value = DateTime.Now.ToString()
aCookie.Expires = DateTime.Now.AddDays(1)
Response.Cookies.Add(aCookie)
 
 
访问Cookie方法(1)
If Not Request.Cookies("userName") Is Nothing Then
Label1.Text = Server.HtmlEncode(Request.Cookies("userName").Value)访问Cookie方法(2)
End If
If Not Request.Cookies("userName") Is Nothing Then
Dim aCookie As HttpCookie =  Request.Cookies("userName")
Label1.Text = Server.HtmlEncode(aCookie.Value)
End If
 
 
创建多值Cookie方法 (1)
Response.Cookies("userInfo")("userName") = “admin"
Response.Cookies("userInfo")("lastVisit") = DateTime.Now.ToString()
Response.Cookies("userInfo").Expires = DateTime.Now.AddDays(1)
 
 
创建多值Cookie方法 (2)
Dim aCookie As HttpCookie =  New HttpCookie("userInfo")
aCookie.Values("userName") = “admin"
aCookie.Values("lastVisit") = DateTime.Now.ToString()
aCookie.Expires = DateTime.Now.AddDays(1)
Response.Cookies.Add(aCookie)
 
 
读取多值Cookie
 
 
Dim aCookie As HttpCookie =  Request.Cookies("userInfo")
Dim userName As String = aCookie.Values(“userName”)
Dim lastVisit As String = aCookie.Values(“lastVisit”)
 
 
修改和删除Cookie
 
不能直接修改或删除Cookie,只能创建一个新的Cookie,发送到客户端以实现修改或删除Cookie.

出处：https://www.cnblogs.com/Fooo/archive/2010/03/26/1697300.html