Asp.net Study(14)
Application,Session,Cookie
Application:设置全局变量，所设变量在整个应用程序范围内有效。
有 Application.Lock() and Application.UnLock() 两个方法。
Session:在Asp中session要依赖于cookie才可运行，但在Asp.net中设置web.config sessionState cookieless="true"则可使session不依赖于cookie
Cookie:实例化一个cookie HttpCookie xxx=new HttpCookie("xxx")
设置单值的cookie,cookie.Value="xxx"
设置多值的cookie,cookie.Value.Add("KeyWord","value")
应用cookie Response.AppendCookie("cookiename")
读取cookie HttpCookie xxx=Request.Cookies("xxx")
设置cookie的过期时间
DateTime xxx=DateTime.Now;
TimeSpan xx=new TimeSpan(x,x,x,x) 分别为天，小时，分钟，秒
cookie.Expires=xxx.Add(xx)
代码：
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<script runat=server>
//Application的应用
public void Page_Load(Object src, EventArgs e)
{
Application.Lock();
Application["User_Count"] = (Int32)Application["User_Count"] + 1;
Application.UnLock();
Count.Text = Application["User_Count"].ToString();
//设置session
Session["Name"] = "John";
Name.Text = Session["Name"].ToString();
//建立一个cookie实例，并对其赋值
HttpCookie cookie = new HttpCookie("John");
DateTime dt = DateTime.Now;
TimeSpan ts = new TimeSpan(0, 0, 2, 0);
cookie.Expires = dt.Add(ts);
cookie.Values.Add("name", "John");
cookie.Values.Add("age", "26");
cookie.Values.Add("sex", "male");
Response.AppendCookie(cookie);
//读取cookie
HttpCookie readcookie = Request.Cookies["John"];
cookie1.Text = readcookie.Values["name"].ToString();
cookie2.Text=readcookie.Values["age"].ToString();
cookie3.Text = readcookie.Values["sex"].ToString();
}
</script>
<title>Application</title>
</head>
<body>
<form id="form1" runat="server">
<div>
The count of viewer is:<asp:Label ID="Count" ForeColor=red runat=server/><br>
Example of Session,Name is:<asp:Label ID="Name" ForeColor=blue runat=server/>
<br>Name:<asp:Label ID="cookie1" runat=server/><br>
Age:<asp:Label ID="cookie2" runat=server/><br>
Sex:<asp:Label ID="cookie3" runat=server/><br>
</div>
</form>
</body>
</html>
