电子商务网站中用cookie保存最近浏览的商品只保存了一个产品

[luoluolhx]

HttpCookie cookie = new HttpCookie("pid");
List<string> list = new List<string>();//放商品id的集合
if (Request.Cookies["pid"] == null)
{
cookie.Value = id;
cookie.Expires = DateTime.Now.AddDays(1);
list.Add(id);
HttpContext.Current.Response.Cookies.Add(cookie);
}
else
{
//判断是否包含重复的id，重复的不加入list中
if (!list.Contains(id))
{
list.Add(id);
}
string aa = "";
foreach (string str in list)
{
aa += str + ",";
}
string bb = aa.Substring(0, aa.Length - 1);//这是list中所有id的字符串
cookie.Value = bb;
cookie.Expires = DateTime.Now.AddDays(1);
HttpContext.Current.Response.Cookies.Add(cookie);

}