MVC学习系列——Filter扩展
在MVC中,Filter也是可以扩展的。在此,本人对Filter的理解就是AOP,不知道各位大侠,有什么高的见解,呵呵。。。
首先MVC四大过滤神器IAuthorizationFilter,IActionFilter,IResultFilter,IExceptionFilter。
在此之前,我们先安装Log4net日志神器:
看下项目的引用
配置文件
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 <?xml version="1.0" encoding="utf-8"?> 2 <configuration> 3 <configSections> 4 <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/> 5 </configSections> 6 <log4net> 7 <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender"> 8 <!--日志路径--> 9 <param name= "File" value= "D:\App_Log\"/> 10 <!--是否是向文件中追加日志--> 11 <param name= "AppendToFile" value= "true"/> 12 <!--log保留天数--> 13 <param name= "MaxSizeRollBackups" value= "10"/> 14 <!--日志文件名是否是固定不变的--> 15 <param name= "StaticLogFileName" value= "false"/> 16 <!--日志文件名格式为:2008-08-31.log--> 17 <param name= "DatePattern" value= "yyyy-MM-dd".log""/> 18 <!--日志根据日期滚动--> 19 <param name= "RollingStyle" value= "Date"/> 20 <layout type="log4net.Layout.PatternLayout"> 21 <param name="ConversionPattern" value="%d [%t] %-5p %c - %m%n %loggername" /> 22 </layout> 23 </appender> 24 <!-- 控制台前台显示日志 --> 25 <appender name="ColoredConsoleAppender" type="log4net.Appender.ColoredConsoleAppender"> 26 <mapping> 27 <level value="ERROR" /> 28 <foreColor value="Red, HighIntensity" /> 29 </mapping> 30 <mapping> 31 <level value="Info" /> 32 <foreColor value="Green" /> 33 </mapping> 34 <layout type="log4net.Layout.PatternLayout"> 35 <conversionPattern value="%n%date{HH:mm:ss,fff} [%-5level] %m" /> 36 </layout> 37 38 <filter type="log4net.Filter.LevelRangeFilter"> 39 <param name="LevelMin" value="Info" /> 40 <param name="LevelMax" value="Fatal" /> 41 </filter> 42 </appender> 43 <root> 44 <!--(高) OFF > FATAL > ERROR > WARN > INFO > DEBUG > ALL (低) --> 45 <level value="all" /> 46 <appender-ref ref="ColoredConsoleAppender"/> 47 <appender-ref ref="RollingLogFileAppender"/> 48 </root> 49 </log4net> 50 <system.web> 51 <compilation debug="true" targetFramework="4.5.2" /> 52 <httpRuntime targetFramework="4.5.2" /> 53 </system.web> 54 </configuration>
增加LogHelper帮助类
1 public class LogHelper 2 { 3 public static void WriteLog_Error(Type t, Exception ex) 4 { 5 log4net.ILog log = log4net.LogManager.GetLogger(t); 6 log.Error("Unhandled exception", ex); 7 } 8 9 public static void WriteLog_Error(Type t, string msg) 10 { 11 log4net.ILog log = log4net.LogManager.GetLogger(t); 12 log.Error(msg); 13 } 14 15 public static void WriteLog_Info(Type t, string msg) 16 { 17 log4net.ILog log = log4net.LogManager.GetLogger(t); 18 log.Info(msg); 19 } 20 }
还有一个重要的一步,在Gobal类中,要申明:
1 //加载配置文件 2 var logCfg = new FileInfo(AppDomain.CurrentDomain.BaseDirectory + "Log4Net.config"); 3 XmlConfigurator.ConfigureAndWatch(logCfg);
ok,到这里log4net,配置完成。
现在,我来扩展IExceptionFilter这个过滤器。
新建Log4NetExceptionFilter类,继承接口IExceptionFilter
1 public class Log4NetExceptionFilter : IExceptionFilter 2 { 3 public void OnException(ExceptionContext filterContext) 4 { 5 LogHelper.WriteLog_Error(GetType(), filterContext.Exception); 6 } 7 }
在FilterConfig中申明自己的异常处理:
1 public class FilterConfig 2 { 3 public static void RegisterGlobalFilters(GlobalFilterCollection filters) 4 { 5 //filters.Add(new HandleErrorAttribute()); 6 //加上自己的异常 7 filters.Add(new Log4NetExceptionFilter()); 8 } 9 }
测试:在HomeController的GetXmlResult,手工增加异常:
1 public XmlResult GetXmlResult() 2 { 3 int a = 1; 4 int b = 0; 5 int c = a / b; 6 7 StudentViewModel viewModel = new StudentViewModel(); 8 viewModel.ID = "1"; 9 viewModel.Name ="Zhangsan"; 10 viewModel.Gender = "Man"; 11 12 return new XmlResult(viewModel); 13 }
结果:
在介绍一下ActionFilterAttribute,这个特性有两个接口IActionFilter, IResultFilter。
因此,新建MyActionFilterAttribute,继承于ActionFilterAttribute
1 public class MyActionFilterAttribute: ActionFilterAttribute 2 { 3 public override void OnActionExecuting(ActionExecutingContext filterContext) 4 { 5 LogHelper.WriteLog_Info(GetType(), "OnActionExecuting"); 6 base.OnActionExecuting(filterContext); 7 } 8 public override void OnActionExecuted(ActionExecutedContext filterContext) 9 { 10 LogHelper.WriteLog_Info(GetType(), "OnActionExecuted"); 11 base.OnActionExecuted(filterContext); 12 } 13 14 public override void OnResultExecuting(ResultExecutingContext filterContext) 15 { 16 LogHelper.WriteLog_Info(GetType(), "OnResultExecuting"); 17 base.OnResultExecuting(filterContext); 18 } 19 20 public override void OnResultExecuted(ResultExecutedContext filterContext) 21 { 22 LogHelper.WriteLog_Info(GetType(), "OnResultExecuted"); 23 base.OnResultExecuted(filterContext); 24 } 25 }
测试:在HomeController的GetXmlResult的方法上,增加MyActionFilterAttribute特性。ps:这里已经去掉刚刚手工增加的异常。
[MyActionFilterAttribute] public XmlResult GetXmlResult() { StudentViewModel viewModel = new StudentViewModel(); viewModel.ID = "1"; viewModel.Name ="Zhangsan"; viewModel.Gender = "Man"; return new XmlResult(viewModel); }
结果: