ASP.NET MVC2.0 自定义filters

今天大家共同学习下ASP.NET MVC2.0中自定义filters,这一节主要学习下ActionFilterAttribute，

ActionFilterAttribute继承IActionFilter, IResultFilter接口,并且继承FilterAttribute类.

ActionFilterAttribute可以监控action执行过程中所有阶段，包括日志，异常处理等功能.

主要包括以下四个重载方法

OnActionExecuting，OnActionExecuted，OnResultExecuting，OnResultExecuted

1.OnActionExecuting是在action开始前执行

用于身份验证和服务器端缓存输出

2. OnActionExecuted在action结束后执行

主要用于异常处理

3. OnResultExecuting在返回result前执行

主要用于设置客户端缓存和服务器端压缩

4. OnResultExecuted在返回result后执行

主要用于异常处理和页面尾部输出调试信息

以下两个DEMO，将展示actionfilter的具体用法

demo1:

在这个DEMO中我们将展示action在各个阶段的执行时间，并在页面中输出。

首先我们定义一个ActionLogAttribute类

1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Web;
5. using System.Web.Mvc;
6. namespace MvcAppOne.ActionFilters
7. {
8. publicclass ActionLogAttribute : ActionFilterAttribute
9. {
10. /// <summary>
11. /// 表示actionID
12. /// </summary>
13. publicint ID
14. {
15. get;
16. set;
17. }
18. /// <summary>
19. /// 在 action开始前执行
20. /// </summary>
21. /// <param name="filterContext"></param>
22. publicoverridevoid OnActionExecuting(ActionExecutingContext filterContext)
23. {
24. filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":actinon开始执行" + DateTime.Now.ToString() + "<br/>");
25. base.OnActionExecuting(filterContext);
26. }
27. /// <summary>
28. /// 在action结束后执行
29. /// </summary>
30. /// <param name="filterContext"></param>
31. publicoverridevoid OnActionExecuted(ActionExecutedContext filterContext)
32. {
33. filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":actinon执行结束" + DateTime.Now.ToString() + "<br/>");
34. base.OnActionExecuted(filterContext);
35. }
36. /// <summary>
37. /// 在result开始前执行
38. /// </summary>
39. /// <param name="filterContext"></param>
40. publicoverridevoid OnResultExecuting(ResultExecutingContext filterContext)
41. {
42. filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":result执行开始" + DateTime.Now.ToString() + "<br/>");
43. base.OnResultExecuting(filterContext);
44. }
45. /// <summary>
46. /// 在result结束后执行
47. /// </summary>
48. /// <param name="filterContext"></param>
49. publicoverridevoid OnResultExecuted(ResultExecutedContext filterContext)
50. {
51. filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":result执行结束" + DateTime.Now.ToString() + "<br/>");
52. base.OnResultExecuted(filterContext);
53. }
54. }
55. }

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

namespace MvcAppOne.ActionFilters
{
    public class ActionLogAttribute : ActionFilterAttribute
    {
        /// <summary>
        /// 表示actionID
        /// </summary>
        public int ID
        {
            get;
            set;
        }
        /// <summary>
        /// 在 action开始前执行
        /// </summary>
        /// <param name="filterContext"></param>
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":actinon开始执行" + DateTime.Now.ToString() + "<br/>");
            base.OnActionExecuting(filterContext);
        }

        /// <summary>
        /// 在action结束后执行
        /// </summary>
        /// <param name="filterContext"></param>
        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":actinon执行结束" + DateTime.Now.ToString() + "<br/>");
            base.OnActionExecuted(filterContext);
        }

        /// <summary>
        /// 在result开始前执行
        /// </summary>
        /// <param name="filterContext"></param>
        public override void OnResultExecuting(ResultExecutingContext filterContext)
        {
            filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":result执行开始" + DateTime.Now.ToString() + "<br/>");
            base.OnResultExecuting(filterContext);
        }

        /// <summary>
        /// 在result结束后执行
        /// </summary>
        /// <param name="filterContext"></param>
        public override void OnResultExecuted(ResultExecutedContext filterContext)
        {
            filterContext.RequestContext.HttpContext.Response.Write(ID.ToString()+":result执行结束" + DateTime.Now.ToString() + "<br/>");
            base.OnResultExecuted(filterContext);
        }

    }
}

然后我们建立一个VIEW页面，ShowNews页面

然后再建立一个ACTION，并把属性标记在action上面

1. [ActionFilters.ActionLog(ID=3)]
2. public ActionResult ShowNews()
3. {
4. return View();
5. }

 [ActionFilters.ActionLog(ID=3)]
        public ActionResult ShowNews()
        {
            return View();
        }

此时我们运行ShowNews页面，我们将看到如下效果

demo2: 接着我们看第二个DEMO,在这个demo中，我们将展现actionFILTER中各个方法的作用

我们建一个类 ActionDealAttribute

1. publicclass ActionDealAttribute : ActionFilterAttribute
2. {
3. publicoverridevoid OnActionExecuting(ActionExecutingContext filterContext)
4. {
5. //用户没有验证通过,转向登录页面
6. if (!filterContext.RequestContext.HttpContext.User.Identity.IsAuthenticated)
7. {
8. filterContext.Result = new RedirectResult("../account/logon");
9. }
10. }
11. publicoverridevoid OnActionExecuted(ActionExecutedContext filterContext)
12. {
13. //异常处理
14. if (filterContext.Exception!=null)
15. {
16. filterContext.ExceptionHandled=true;
17. filterContext.Result = new RedirectResult("../shared/Error");//转向错误页面
18. }
19. }
20. publicoverridevoid OnResultExecuting(ResultExecutingContext filterContext)
21. {
22. base.OnResultExecuting(filterContext);
23. }
24. publicoverridevoid OnResultExecuted(ResultExecutedContext filterContext)
25. {
26. base.OnResultExecuted(filterContext);
27. }
28. }

public class ActionDealAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            //用户没有验证通过,转向登录页面
            if (!filterContext.RequestContext.HttpContext.User.Identity.IsAuthenticated)
            {
                filterContext.Result = new RedirectResult("../account/logon");
            }
        }

        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            //异常处理
            if (filterContext.Exception!=null)
            {
                filterContext.ExceptionHandled=true;
                filterContext.Result = new RedirectResult("../shared/Error");//转向错误页面
            }

        }

        public override void OnResultExecuting(ResultExecutingContext filterContext)
        {
            base.OnResultExecuting(filterContext);
        }

        public override void OnResultExecuted(ResultExecutedContext filterContext)
        {
            base.OnResultExecuted(filterContext);
        }

    }

再建立一个news页面，并建立一个对应的action

如果访问news页面需要登录才能访问，就在news对应的action标记此属性，在OnActionExecuting中进行处理

1. [ActionFilters.ActionDeal]
2. public ActionResult News()
3. {
4. return View();
5. }

[ActionFilters.ActionDeal]
        public ActionResult News()
        {
            return View();
        }

如果news页面访问的时候出现异常，就会转向错误页面，在OnActionExecuted中进行处理

1. [ActionFilters.ActionDeal]
2. publicvoid News()
3. {
4. thrownew Exception();
5. }

        [ActionFilters.ActionDeal]
        public void News()
        {
            throw new Exception();
        }

以上只是自定义action的简单用法，供大家参考。

代码下载:http://download.csdn.net/detail/zx13525079024/4375094