功能:MVC提供过滤器Filter,使开发者不用复杂的实现AOP而直接用Filter实现同样的功能.

实现:1.定义一个类实现ActionFilterAttribute,重载借口中的方法后在Controller或者Action上加上该特性即可

2.若是每个Action都要实现,则可以在全局文件中,在注册过滤器"RegisterGlobalFilters(GlobalFilters.Filters);"之前使用GlobalFilters.Filters.Add方法加入定义好的过滤对象的实现

例子:

1.先定义过滤器类

[AttributeUsage(AttributeTargets.All,AllowMultiple=true)]//此属性让他可以执行多次    public class DemoActionAttributeFileter : ActionFilterAttribute    {        public string strMsg { get; set; }        public override void OnActionExecuting(ActionExecutingContext filterContext)        {            filterContext.HttpContext.Response.Write("");            base.OnActionExecuting(filterContext);        }        public override void OnActionExecuted(ActionExecutedContext filterContext)        {            filterContext.HttpContext.Response.Write("");            base.OnActionExecuted(filterContext);        }    }

2.使用该特性

[MyMVC3Test.Filter.DemoActionAttributeFileter(strMsg = "hello")]    public class HomeController : Controller    {        [MyMVC3Test.Filter.DemoActionAttributeFileter(strMsg = "Actionhello")]        public ActionResult Index(string strHome)        {            ViewBag.Message = "欢迎使用 ASP.NET MVC----"+strHome;            ViewBag.Msg = "hehe";            return View();        }        public ActionResult About()        {            return View();        }    }

3.全局过滤器使用

protected void Application_Start()        {            AreaRegistration.RegisterAllAreas();            GlobalFilters.Filters.Add(new MyMVC3Test.Filter.DemoActionAttributeFileter(){strMsg="全局"});            RegisterGlobalFilters(GlobalFilters.Filters);            RegisterRoutes(RouteTable.Routes);        }