Cookies用法

public partial class glassku_Default : System.Web.UI.Page  
{  
    protected void Page_Load(object sender, EventArgs e)  
    {  
        if (!IsPostBack)//如果页面不是回调，则执行Add语句；再点击Button1_Click事件，执行二次加载，就不再执行Add语句了。  
        {  
            DropDownList1.Items.Add("北京");  
            DropDownList1.Items.Add("上海");  
            DropDownList1.Items.Add("杭州");  
            DropDownList1.Items.Add("成都");  
            DropDownList1.Items.Add("重庆");  
            //建立单值Cookies  
            //法一：  
            HttpCookie mycookie1 = new HttpCookie("c1");  
            mycookie1.Value = "zhang";  
            mycookie1.Expires = DateTime.Now.AddDays(1);  
            Response.Cookies.Add(mycookie1);  
 
            //法二：  
            HttpCookie mycookie2 = new HttpCookie("c2", "zhangyj");  
            mycookie2.Expires = DateTime.Now.AddDays(1);  
            Response.Cookies.Add(mycookie2);  
 
            // 法三：  
            Response.Cookies["username"].Value = Server.UrlEncode("张亚京");  
            Response.Cookies["username"].Expires = DateTime.Now.AddDays(1);  
 
 
            //建立多值Cookies  
            //法一：  
            HttpCookie mycookie3 = new HttpCookie("a");  
            mycookie3.Values["a1"] = "zhang";  
            mycookie3.Values["a2"] = "yj";  
            mycookie3.Expires = DateTime.Now.AddDays(1);  
            Response.Cookies.Add(mycookie3);  
 
            // 法二：  
            Response.Cookies["b"]["b1"] = "zhang";  
            Response.Cookies["b"]["b2"] = "yajing";  
            Response.Cookies["b"].Expires = DateTime.Now.AddDays(1);  
 
              
       }  
    }  
    protected void Button1_Click(object sender, EventArgs e)  
    {  
        Label1.Text = Request.Cookies["c1"].Value + "<br>" 
            + Request.Cookies["c2"].Value + "<br>" 
            + Server.UrlDecode(Request.Cookies["username"].Value) + "<br>" 
            + Request.Cookies["a"].Value + "<br>" 
            + Request.Cookies["b"].Value + "<br>" 
            + "选择的城市是：" + DropDownList1.SelectedValue.ToString();  
    }   
 }

页面输出结果如下：

北京 上海 杭州 成都 重庆
zhang
zhangyj
张亚京
a1=zhang&a2=yj
b1=zhang&b2=yajing
选择的城市是：北京

//读取 Cookie 集合
for(int i = 0 ;i<Request.Cookies.Count ;i++)
{
    HttpCookie cookies = Request.Cookies[i];
    Response.Write("name="+cookies.Mame+"<br>");
    if (cookies.HasKeys )//是否有子键
    {
        System.Collections.Specialized.NameValueCollection NameColl
                                             = aCookie.Values ;
        for(int j=0;j<NameColl.Count;j++)
        {
            Response.Write("子键名="+ NameColl.AllKey[j] +"<br>");
            Response.Write("子键值="+ NameColl[j] +"<br>");
        }

 

    }
    else
    {
        Response.Write("value="+cookies.Value+"<br>");       
    }
}