.net mvc 扩展IPrincipal接口

 .自定义实现IPrincipal接口的类
  interface ICustomPrincipal : IPrincipal
 {
     string Identifier { get; set; }
     string IdentityType { get; set; }
 }
 public class CustomPrincipal : ICustomPrincipal
 {
     public IIdentity Identity { get; private set; }
     public bool IsInRole(string role) { return false; }
     public CustomPrincipal()
     {
     }
     public CustomPrincipal(string identifer)
     {
         this.Identity = new GenericIdentity(identifer);
     }

     public  CustomPrincipal(IIdentity identity)
     {
         this.Identity = identity;
     }

     public string Identifier
     {
         get;
         set;
     }

     public string IdentityType
     {
         get;
         set;
     }
 }
 public class CustomPrincipalSerializeModel
 {
     public string Identifier { get; set; }
     public string IdentityType { get; set; }
 }
 .登录成功，存储相关登录信息
 CustomPrincipalSerializeModel serializeModel = new CustomPrincipalSerializeModel();
 serializeModel.Identifier = model.Account;
 serializeModel.IdentityType = "email";

 JavaScriptSerializer serializer = new JavaScriptSerializer();

 string userData = serializer.Serialize(serializeModel);

 FormsAuthenticationTicket authTicket = new FormsAuthenticationTicket(
          ,
          model.Account,
          DateTime.Now,
          DateTime.Now.AddMinutes(),
          false,
          userData);

 string encTicket = FormsAuthentication.Encrypt(authTicket);
 HttpCookie faCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encTicket);
 Response.Cookies.Add(faCookie);
 .在Global文件中注册Application_PostAuthenticateRequest事件
 protected void Application_PostAuthenticateRequest(Object sender, EventArgs e)
 {
     HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];

     if (authCookie != null)
     {
         FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);

         JavaScriptSerializer serializer = new JavaScriptSerializer();

         CustomPrincipalSerializeModel serializeModel = serializer.Deserialize<CustomPrincipalSerializeModel>(authTicket.UserData);

         CustomPrincipal newUser = new CustomPrincipal(authTicket.Name);
         newUser.Identifier = serializeModel.Identifier;
         newUser.IdentityType = serializeModel.IdentityType;

         HttpContext.Current.User = newUser;
     }

 }
 .在BaseController中获取登录相关信息
 protected virtual new CustomPrincipal User
 {
     get { return HttpContext.User as CustomPrincipal; }
 }
 .方法中使用
 User.Identifier