过滤器又叫筛选器，一般有三种过滤器，一个是aciton过滤器，也就是执行action之前和之后，还一种是view过滤器，就是加载view之前和之后，最后一种就是异常过滤器，是异常后触发的。
很简单，只要类实现了ActionFilterAttribute这个接口，并重写里面的方法便可。上代码，一看便知
原文地址：http://www.cnblogs.com/sixiangqimeng/p/3567716.html
public class MyActionFileterAttribute :ActionFilterAttribute { public string Name { get; set; } //当Action执行之前先执行此代码 public override void OnActionExecuting(ActionExecutingContext filterContext) { base.OnActionExecuting(filterContext); filterContext.HttpContext.Response.Write("<p>当前是：OnActionExecuting by "+Name+"</p>"); } public override void OnActionExecuted(ActionExecutedContext filterContext) { base.OnActionExecuted(filterContext); filterContext.HttpContext.Response.Write("<p>当前是：OnActionExecuted by " + Name + "</p>"); } public override void OnResultExecuting(ResultExecutingContext filterContext) { base.OnResultExecuting(filterContext); filterContext.HttpContext.Response.Write("<p>当前是：OnResultExecuting by " + Name + "</p>"); } public override void OnResultExecuted(ResultExecutedContext filterContext) { base.OnResultExecuted(filterContext); filterContext.HttpContext.Response.Write("<p>当前是：OnResultExecuted by " + Name + "</p>"); } }
实现时只需在控制器方法上加上[MyActionFileter(Name = "About ")]。
也可以设置全局的，整个项目都设置过滤器，秩序在过滤器设置里面设置
public static void RegisterGlobalFilters(GlobalFilterCollection
filters)
{
filters.Add(new MyExceptionFilterAttribute());
filters.Add(new MyActionFileterAttribute(){Name =
"gloable"});
}
设置一个全局的即可