一个简单的ActionFilter

    [AttributeUsage(AttributeTargets.Class|AttributeTargets.Method,
        Inherited=true,AllowMultiple=true)]
    public class LogAttribute :FilterAttribute,IActionFilter,IResultFilter
    {
        public string LogName { get; set; }

        public void Log(string controller, string action, string msg)
        {
            if (!string.IsNullOrEmpty(LogName))
            {
                TextWriter writer = new StreamWriter(LogName, true);
                writer.WriteLine("Time:{0}", DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss"));
                writer.WriteLine("Controller:{0}", controller);
                writer.WriteLine("Action:{0}", action);
                writer.WriteLine("Msg:{0}", msg);
                writer.WriteLine("System:{0}", System.Environment.OSVersion.Version.ToString());
                writer.WriteLine("ThreadID:{0}", AppDomain.GetCurrentThreadId());
                writer.Close();
            }
        }

        public void OnActionExecuting(ActionExecutingContext filterContext)
        {
            Log(filterContext.RouteData.Values["controller"].ToString(), filterContext.RouteData.Values["action"].ToString(), "Action Executing...");
        }

        public void OnActionExecuted(ActionExecutedContext filterContext)
        {
            Log(filterContext.RouteData.Values["controller"].ToString(), filterContext.RouteData.Values["action"].ToString(), "Action Executed.");
        }

        public void OnResultExecuting(ResultExecutingContext filterContext)
        {
            Log(filterContext.RouteData.Values["controller"].ToString(),
                filterContext.RouteData.Values["action"].ToString(),
                "Result executing...");
        }

        public void OnResultExecuted(ResultExecutedContext filterContext)
        {
            Log(filterContext.RouteData.Values["controller"].ToString(),
                  filterContext.RouteData.Values["action"].ToString(),
                  "Result executed");
        }

    }