ASP.NET MVC的Action拦截器（过滤器）ActionFilter

有时项目要进行客户端请求(action)进行拦截(过滤)验证等业务，可以使用拦截器进行实现，所谓的action拦截器也没有什么的，只是写一个类，继承另一个类（System.Web.Mvc.FilterAttribute）和一个接口(System.Web.Mvc.IActionFilter)，至于什么是拦截器这里就不说了，网上很多关于这方面文章。

假如现在有这样的一个需求：某个action需要登录才能进行访问，可以使用action属性拦截器进行拦截进行验证

多余的不说了直接上代码

 写一个拦截器类：

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Web;
 5 using System.Web.Mvc;
 6 
 7 namespace AttributeDemo.Common
 8 {
 9     /// <summary>
10     /// Action拦截器
11     /// </summary>
12     public class ActionFilterAttribute : System.Web.Mvc.FilterAttribute, System.Web.Mvc.IActionFilter
13     {
14         #region 属性
15         /// <summary>
16         /// 记录是否登陆
17         /// </summary>
18         public bool IsLogin { get; set; }
19         #endregion
20 
21         #region 执行action后执行这个方法
22         /// <summary>
23         /// 执行action后执行这个方法
24         /// </summary>
25         /// <param name="filterContext"></param>
26         void System.Web.Mvc.IActionFilter.OnActionExecuted(System.Web.Mvc.ActionExecutedContext filterContext)
27         {
28 
29         }
30         #endregion
31 
32 
33         #region 执行action前执行这个方法 
34         /// <summary>
35         /// 执行action前执行这个方法
36         /// </summary>
37         /// <param name="filterContext"></param>
38         void System.Web.Mvc.IActionFilter.OnActionExecuting(System.Web.Mvc.ActionExecutingContext filterContext)
39         {
40 
41             if (!this.IsLogin)  //未登陆 重定向 到登陆页面
42             {
43                 if (filterContext.HttpContext.Request.IsAjaxRequest())   //判断是否ajax请求
44                 {
45 
46                     filterContext.Result = new System.Web.Mvc.JsonResult() { Data = new { statusCode = 301 }, ContentEncoding = System.Text.Encoding.UTF8, JsonRequestBehavior = JsonRequestBehavior.AllowGet, ContentType = "json" };
47                     return;
48                 }
49                 else  //验证不通过
50                 {
51                     //filterContext.Result = new RedirectToRouteResult(new System.Web.Routing.RouteValueDictionary(new { controller = "ActionFilterTest", action = "Login" }));  //重定向
52                     //filterContext.Result = new RedirectToRouteResult(new System.Web.Routing.RouteValueDictionary(new Dictionary<string, object>() { { "controller", "ActionFilterTest" }, { "action", "Login" } }));   //重定向
53 
54                     //filterContext.Result = new System.Web.Mvc.RedirectToRouteResult("Default", new System.Web.Routing.RouteValueDictionary(new Dictionary<string, object>() { { "controller", "ActionFilterTest" }, { "action", "Login" } }));    //重定向
55 
56                     //filterContext.Result = new System.Web.Mvc.RedirectToRouteResult("Default", new System.Web.Routing.RouteValueDictionary(new Dictionary<string, object>() { { "controller", "ActionFilterTest" }, { "action", "Login" } }),true);  //重定向
57 
58                     filterContext.Result = new System.Web.Mvc.RedirectToRouteResult("MyRoute", new System.Web.Routing.RouteValueDictionary(new Dictionary<string, object>() { { "controller", "ActionFilterTest" }, { "action", "Login" } }), true);    //重定向
59                     return;
60                 }
61 
62             }
63 
64         }
65         #endregion
66 
67     }
68 }

请求的控制器类：

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Web;
 5 using System.Web.Mvc;
 6 
 7 namespace AttributeDemo.Controllers
 8 {
 9     /// <summary>
10     /// 测试Action拦截器
11     /// </summary>
12     public class ActionFilterTestController : Controller
13     {
14         //
15         // GET: /ActionFilterTest/
16 
17         /// <summary>
18         /// 测试action拦截器
19         /// </summary>
20         /// <returns></returns>
21         [AttributeDemo.Common.ActionFilter(IsLogin = false)]
22         public ActionResult Test()
23         {
24             return View();
25         }
26 
27          
28         public ActionResult Login()
29         {
30             return View();
31         }
32 
33         [AttributeDemo.Common.ActionFilter(IsLogin = true)]
34         public ActionResult Index()
35         {
36             return View();
37         }
38     }
39 }

Global.asax类：

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Web;
 5 using System.Web.Mvc;
 6 using System.Web.Routing;
 7 
 8 namespace AttributeDemo
 9 {
10     // 注意: 有关启用 IIS6 或 IIS7 经典模式的说明，
11     // 请访问 http://go.microsoft.com/?LinkId=9394801
12 
13     public class MvcApplication : System.Web.HttpApplication
14     {
15         public static void RegisterGlobalFilters(GlobalFilterCollection filters)
16         {
17             filters.Add(new HandleErrorAttribute());
18         }
19 
20         public static void RegisterRoutes(RouteCollection routes)
21         {
22             routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
23 
24             routes.MapRoute(
25                 "Default", // 路由名称
26                 "{controller}/{action}/{id}", // 带有参数的 URL
27                 new { controller = "Home", action = "Index", id = UrlParameter.Optional } // 参数默认值
28             );
29             routes.MapRoute(
30                 "MyRoute", // 路由名称
31                 "{controller}/{action}/{id}", // 带有参数的 URL
32                 new { controller = "ActionFilterTest", action = "Login", id = UrlParameter.Optional } // 参数默认值
33             );
34         }
35 
36         protected void Application_Start()
37         {
38             AreaRegistration.RegisterAllAreas();
39 
40             RegisterGlobalFilters(GlobalFilters.Filters);
41             RegisterRoutes(RouteTable.Routes);
42         }
43     }
44 }

 注意：拦截器也可以写在控制器类属性上，写在控制器类上表示拦截该控制器下所有action，如果写在action只是拦截当前action有效

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace AttributeDemo.Controllers
{
    /// <summary>
    /// 测试Action拦截器
    /// </summary>
    [AttributeDemo.Common.ActionFilter(IsLogin = false)]
    public class ActionFilterTestController : Controller
    {
        //
        // GET: /ActionFilterTest/
    }
}