Asp.net mvc 权限过滤和单点登录（禁止重复登录）

/// <summary>
/// 用户权限控制
/// </summary>
public class UserAuthorize : AuthorizeAttribute
{
  /// <summary>
  /// 授权失败时呈现的视图
  /// </summary>
  public string AuthorizationFailView { get; set; }
  /// <summary>
  /// 请求授权时执行
  /// </summary>
  /// <param name="filterContext">上下文</param>
  public override void OnAuthorization(AuthorizationContext filterContext)
  {
    // 获取url请求里的 controller 和 action
    string controllerName = filterContext.RouteData.Values["controller"].ToString();
    string actionName = filterContext.RouteData.Values["action"].ToString();
    // 获取用户信息
    UserLoginBaseInfo _userLoginInfo = filterContext.HttpContext.Session[Property.UerLoginSession] as UserLoginBaseInfo;
    //根据请求过来的controller和action去查询可以被哪些角色操作: 这是查询数据库 roleid使用 1,2,3,4格式
    RoleWithControllerAction roleWithControllerAction =
      SampleData.roleWithControllerAndAction.FirstOrDefault(r => r.ControllerName.ToLower() == controllerName.ToLower() && r.ActionName.ToLower() == actionName.ToLower() && r.RoleIds.contails("3"));
    // 有值处理
    if (roleWithControllerAction != null)
    {
      //有权限操作当前控制器和Action的角色id
      this.Roles = roleWithControllerAction.RoleIds;
    }
    else
    {
      //请求失败输出空结果
      filterContext.Result = new EmptyResult();
      //打出提示文字
      HttpContext.Current.Response.Write("对不起,你没有权限操作!");
    }
    base.OnAuthorization(filterContext);
  }
  /// <summary>
  /// 自定义授权检查（返回False则授权失败）
  /// </summary>
  protected override bool AuthorizeCore(HttpContextBase httpContext)
  {
    //if (httpContext.User.Identity.IsAuthenticated)
    //{
    //  string userName = httpContext.User.Identity.Name;  //当前登录用户的用户名
    //  User user = SampleData.users.Find(u => u.UserName == userName);  //当前登录用户对象
    //  if (user != null)
    //  {
    //    Role role = SampleData.roles.Find(r => r.Id == user.RoleId); //当前登录用户的角色
    //    foreach (string roleid in Roles.Split(','))
    //    {
    //      if (role.Id.ToString() == roleid)
    //        return true;
    //    }
    //    return false;
    //  }
    //  else
    //    return false;
    //}
    //else
    //  return false;   //进入HandleUnauthorizedRequest
    return true;
  }
  /// <summary>
  /// 处理授权失败的HTTP请求
  /// </summary>
  protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
  {
    if (string.IsNullOrWhiteSpace(AuthorizationFailView))
      AuthorizationFailView = "error";
    filterContext.Result = new ViewResult { ViewName = AuthorizationFailView };
  }
}

/// <summary>
/// 限制一个用户只能登陆一次
/// </summary>
/// <returns></returns>
private void GetOnline()
{
  string UserID = "1";
  Hashtable SingleOnline = (Hashtable)System.Web.HttpContext.Current.Application[Property.Online];
  if (SingleOnline == null)
    SingleOnline = new Hashtable();
  IDictionaryEnumerator idE = SingleOnline.GetEnumerator();
  string strKey = string.Empty;
  while (idE.MoveNext())
  {
    if (idE.Value != null && idE.Value.ToString().Equals(UserID))
    {
      //already login 
      strKey = idE.Key.ToString();
      //当前用户已存在移除、
      SingleOnline.Remove(strKey);
      System.Web.HttpContext.Current.Application.Lock();
      System.Web.HttpContext.Current.Application[Property.Online] = SingleOnline;
      System.Web.HttpContext.Current.Application.UnLock();
      break;
    }
  }
  //SessionID
  if (!SingleOnline.ContainsKey(Session.SessionID))
  {
    SingleOnline[Session.SessionID] = UserID;
    System.Web.HttpContext.Current.Application.Lock();
    System.Web.HttpContext.Current.Application[Property.Online] = SingleOnline;
    System.Web.HttpContext.Current.Application.UnLock();
  }
}

/// <summary>
 /// 用户基础信息过滤器
 /// </summary>
 public class LoginActionFilter : ActionFilterAttribute
 {
   /// <summary>
   /// 初始化地址
   /// </summary>
   public const string Url = "~/Login/Index";
   /// <summary>
   /// 该方法会在action方法执行之前调用 
   /// </summary>
   /// <param name="filterContext">上下文</param>
   public override void OnActionExecuting(ActionExecutingContext filterContext)
   {
     // 获取上一级url
     // var url1 = filterContext.HttpContext.Request.UrlReferrer;
     UserLoginBaseInfo _userLogin = filterContext.HttpContext.Session[Property.UerLoginSession] as UserLoginBaseInfo;
     // 用户是否登陆
     if (_userLogin == null)
     {
       filterContext.Result = new RedirectResult(Url + "登陆时间过期,请重新登陆!&url=" + filterContext.HttpContext.Request.RawUrl);
     }
     else
     {
       filterContext.HttpContext.Session.Timeout = 30;
     }
     //判断是否在其它地方登录
     Hashtable singleOnline = (Hashtable)System.Web.HttpContext.Current.Application[Property.Online];
     // 判断当前SessionID是否存在
     if (singleOnline != null && !singleOnline.ContainsKey(HttpContext.Current.Session.SessionID))
       filterContext.Result = new RedirectResult(Url + "你的帐号已在别处登陆，你被强迫下线!");
     base.OnActionExecuting(filterContext);
   }
   /// <summary>
   /// 执行后
   /// </summary>
   /// <param name="filterContext"></param>
   public override void OnResultExecuting(ResultExecutingContext filterContext)
   {
     //记录操作日志，写进操作日志中
     var controllerName = filterContext.RouteData.Values["controller"];
     var actionName = filterContext.RouteData.Values["action"];
     base.OnResultExecuting(filterContext);
   }

/// <summary>
/// Session销毁
/// </summary>
protected void Session_End()
{
  Hashtable SingleOnline = (Hashtable)Application[Property.Online];
  if (SingleOnline != null && SingleOnline[Session.SessionID] != null)
  {
    SingleOnline.Remove(Session.SessionID);
    Application.Lock();
    Application[Property.Online] = SingleOnline;
    Application.UnLock();
  }
  Session.Abandon();
}