1.写入Cookie值

string userName = context.Request.Form["u_Name"].ToString().Trim();
string pwd = context.Request.Form["u_Pwd"].ToString().Trim();

if (userName != "" && pwd != "")
{
  Users u = UsersDal.m_UserDal.GetModel(string.Format(" u_Name = ‘{0}‘ and u_Pwd = ‘{1}‘", userName, pwd));
if (u != null)
{
  //设置Cookie值,有效期为两个小时
  HttpCookie cookie = new HttpCookie("UserInfor");
  cookie.Value = http://www.mamicode.com/userName +"," + pwd + "," + u.u_DeId;
  HttpContext.Current.Response.Cookies.Add(cookie);
  cookie.Expires = DateTime.Now.AddHours(2);

}
else
{
  infor = "用户名或密码错误，请确认";

}

}

2.获取Cookie值
  HttpCookie cookie = HttpContext.Current.Request.Cookies["UserInfor"];
  if (cookie == null)
 {
   infor = "您还未登录，请先登录";
 }
  else
 {
  string userInfor = cookie.Value;
  if (!string.IsNullOrEmpty(userInfor))
{
  string[] arr = userInfor.Split(‘,‘);
  string userName = arr[0];
  string pwd = arr[1];
  string deId = arr[2];
  Users u = UsersDal.m_UserDal.GetModel(string.Format(" u_Name = ‘{0}‘ and u_Pwd = ‘{1}‘", userName, pwd));

  ........

}

3.清除Cookie值

HttpCookie Cookie = new HttpCookie("UserInfor");
Cookie.Expires = DateTime.Now.AddHours(-2);
context.Response.Cookies.Add(Cookie);

Cookie的写入、读取、清除