MVC自定义过滤器

   /// <summary>
        /// MVC自定义过滤器
        /// </summary>
        public class LoggingFilterAttribute : ActionFilterAttribute
        {
            public override void OnActionExecuting(ActionExecutingContext
       filterContext)
            {
                filterContext.HttpContext.Trace.Write("Starting:"+
                    filterContext.ActionDescriptor.ActionName);
            }
            //错误过滤器
            public override void OnActionExecuted(ActionExecutedContext
       filterContext)
            {
                if (filterContext.Exception != null)
                {
                    filterContext.HttpContext.Trace.Write("Exception thrown");
                }
            }
        }

引用：

       [LoggingFilterAttribute]
        public ActionResult Index(string type)
        {

            //故意引发错误，则自动会执行 LoggingFilterAttribute过滤器中的OnActionExecuted方法</span>
            int i = 7, j = 0;
            int c = i/j;
            return View();
        }