asp.net中cookie使用

//写入
protected void Button2_Click(object sender, EventArgs e)
{
HttpCookie cookie=new HttpCookie("MyCook");//初使化并设置Cookie的名称
DateTime dt=DateTime.Now;
TimeSpan ts = new TimeSpan(0, 0, 1,0,0);//过期时间为1分钟
cookie.Expires = dt.Add(ts);//设置过期时间
cookie.Values.Add("userid", "userid_value");
cookie.Values.Add("userid2","userid2_value2");
Response.AppendCookie(cookie);
//输出该Cookie的所有内容
//Response.Write(cookie.Value); //输出为：userid=userid_value&userid2=userid2_value2
}

//读取
protected void Button1_Click(object sender, EventArgs e)
{

// HttpCookie cokie = new HttpCookie("MyCook");//初使化
if (Request.Cookies["MyCook"]!=null)
{
//Response.Write("Cookie中键值为userid的值:" + Request.Cookies["MyCook"]["userid"]);//整行
//Response.Write("Cookie中键值为userid2的值" + Request.Cookies["MyCook"]["userid2"]);
Response.Write(Request.Cookies["MyCook"].Value);//输出全部的值
}
}

//修改Cookie
protected void Button3_Click(object sender, EventArgs e)
{
//获取客户端的Cookie对象
HttpCookie cok = Request.Cookies["MyCook"];

if (cok != null)
{
//修改Cookie的两种方法
cok.Values["userid"] = "alter-value";
cok.Values.Set("userid", "alter-value");

//往Cookie里加入新的内容
cok.Values.Set("newid", "newValue");
Response.AppendCookie(cok);
}

}
//删除Cookie
protected void Button4_Click(object sender, EventArgs e)
{

HttpCookie cok = Request.Cookies["MyCook"];
if (cok != null)
{
if (!CheckBox1.Checked)
{
cok.Values.Remove("userid");//移除键值为userid的值
}
else
{
TimeSpan ts = new TimeSpan(-1, 0, 0, 0);
cok.Expires = DateTime.Now.Add(ts);//删除整个Cookie，只要把过期时间设置为现在
}
Response.AppendCookie(cok);
}
}