//override OnException方法
        public override void OnException(object sender, PolicyInjectionAttributeEventArgs e)
        {
            var msg = $"\r\n exception({DateTime.Now.ToString()}) : \r\n{e.Exception.Message }";

            //Console.Write(msg);
            SaveLog(msg);
        }
        //override AfterInvoke方法
        public override void AfterInvoke(object sender, PolicyInjectionAttributeEventArgs e)
        {
            var msg = $"\r\n Method '{e.MethodBase.Name}' has been called - {DateTime.Now.ToString()} ";

            SaveLog(msg);
        }