【IT168技术】现在的企业级开发项目，特别是网站一般都会用到log功能，想想大部分会用Enterprise Logging Application Block 的功能 或者自己写一个组件，记录系统日志事件，更好的跟踪了解系统运行情况, 现用ASP.NET MVC 的过滤属性实现log功能!
ASP.NET MVC的filter 是一个属性，可以应用到controller 后者action.当Controller或者action method 被调用时，ASP.NET MVC的filter在调用执行前后会被触发。 先看下当Control 里面的action 被调用时的利用继承,自定义类log的效果图：
要实现上面的效果，现自定义一个类LogMessageAttribute,LogMessageAttribute继承接口IActionFilter ,IResultFilter,也可以选择性的继承重写类FilterAttribute。
IActionFilter interface 定义为：
public interface IActionFilter { // Methods void OnActionExecuted(ActionExecutedContext filterContext); void OnActionExecuting(ActionExecutingContext filterContext); } OnActionExecuting
：在Controller 里面的action method 调用之前运行
OnActionExecuted：在Controller 里面的action method 调用之后运行，但是在IResultFilter接口的OnResultExecuting方法执行之前
IResultFilter interface定义为：
public interface IResultFilter { // Methods void OnResultExecuted(ResultExecutedContext filterContext); void OnResultExecuting(ResultExecutingContext filterContext); } OnResultExecuting
：在Controller 里面的action method调用处理玩前执行.
OnResultExecuted：在Controller 里面的action method调用处理玩后执行.
接下来是重头戏：LogMessageAttribute自定义类
[AttributeUsage(AttributeTargets.Class |AttributeTargets.Method ,Inherited=true ,AllowMultiple=true )] public class LogMessageAttribute:FilterAttribute,IActionFilter,IResultFilter { /// /// 日志文件路径 /// public string LogName { get; set; } /// /// 记录时间，系统版本，当前线程ID 等记录 /// /// /// /// public void LogMessage(string controller, string action, string message) { if (!string.IsNullOrEmpty(LogName)) { TextWriter writer = new StreamWriter(LogName, true); writer.WriteLine("################# Begin #################"); writer.WriteLine("Time:[{0}]",DateTime.Now.ToString("yyyy-MM-dd- hh:mm:ss")); writer.WriteLine("Controller:{0}",controller); writer.WriteLine("Action:{0}",action); writer.WriteLine("Message:{0}",message); writer.WriteLine("Operating System version is:{0}",System.Environment.OSVersion.Version.ToString()); writer.WriteLine("Current Thread ID is:{0}",AppDomain.GetCurrentThreadId()); writer.WriteLine("############### Over ###############"); writer.Close(); } } public void OnActionExecuting(ActionExecutingContext filterContext) { LogMessage(filterContext.RouteData.Values["controller"].ToString(), filterContext.RouteData.Values["action"].ToString(), "Action exeuting..."); } public void OnActionExecuted(ActionExecutedContext filterContext) { LogMessage(filterContext.RouteData.Values["controller"].ToString(), filterContext.RouteData.Values["action"].ToString(), "Action executed."); } public void OnResultExecuting(ResultExecutingContext filterContext) { LogMessage(filterContext.RouteData.Values["controller"].ToString(), filterContext.RouteData.Values["action"].ToString(), "Result executing..."); } public void OnResultExecuted(ResultExecutedContext filterContext) { LogMessage(filterContext.RouteData.Values["controller"].ToString(), filterContext.RouteData.Values["action"].ToString(), "Result executed"); } }
自定义好LogMessageAttribute类，应用到Controller或者action的属性。在Controller 正在执行，或者呈现一个View,一个HTTP请求数据时，就会在日志文件记录一些日志.
在项目的Controller里面应用自定义的属性
[Logging(LogName = @"D:\Project\Project\MVCProject\sky.ExtendMVCFramework\sky.ExtendMVCFramework\Log.log")] public ActionResult DesplayEmployee() { ViewData["Message"] = "Our employees welcome you to our site!"; List employees = new List { new Employee { FirstName="sky", LastName="yang", Email = "weflytotti@163.com", Department ="Development" }, new Employee { FirstName="sky", LastName="yang", Email = "weflytotti@163.com", Department ="Development" } }; return View(employees); }
运行程序，正如文章开始所看到的截图!
总结：自定义ASP.NET MVC 的过滤属性实现自己想要的功能只需要继承IActionFilter ,IResultFilter。
