自定以身份认证

自定以身份认证需要继承IIdentity与IPrincipal这两个接口来实现，这个过程是在AuthenticateRequest阶段完成的。以下过程都是模拟实现身份认证的，通过这种方式可以将ticket中保存的数据取出来用于初始化IPrincipal的实现，从而改变HttpContext.Current.User的指向的对象实例。

  <authentication mode="Forms">
            <forms loginUrl="a.html" name="andy"></forms>
        </authentication>

    public class MyPrincipal : IPrincipal
    {
        public IIdentity Identity
        {
            get { return new MyIdendity("aa"); }
        }

        public bool IsInRole(string role)
        {
            if (string.Compare(role, "a,b", true) == 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }

  public class MyIdendity : IIdentity
    {

        public MyIdendity(string data)
        { 
          
        }
        public string AuthenticationType
        {
            get { return "MyIdendity"; }
        }

        public bool IsAuthenticated
        {
            get { return true; }
        }

        public string Name
        {
            get { return "andy"; }
        }
    }

  protected void Page_Load(object sender, EventArgs e)
        {
            string userRoles = "admin,test";
            FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
                1,
                "a",
                DateTime.Now,
                DateTime.Now.AddMinutes(30),
                true,
               userRoles,
               "/"
                );
            string haskTicket = FormsAuthentication.Encrypt(ticket);
            HttpCookie userCookie = new HttpCookie(FormsAuthentication.FormsCookieName,haskTicket);
            Response.Cookies.Add(userCookie);
        
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            var context = HttpContext.Current;
            if (context.User.Identity is FormsIdentity)
            {
                if (!(context.User is MyPrincipal))
                {
                    FormsIdentity forms = (FormsIdentity)context.User.Identity;
                    string data = forms.Ticket.UserData;
                    MyPrincipal principal = new MyPrincipal();
                    context.User = principal;
                }
            }
        }
    }