public override void OnException(ExceptionContext filterContext) { if (!filterContext.ExceptionHandled) { string controllerName = (string)filterContext.RouteData.Values["controller"]; string actionName = (string)filterContext.RouteData.Values["action"]; string param = Common.GetPostParas(); string ip = HttpContext.Current.Request.UserHostAddress; LogManager.GetLogger("LogExceptionAttribute").Error("Location：{0}/{1} Param：{2}UserIP：{3} Exception：{4}", controllerName, actionName, param, ip, filterContext.Exception.Message); filterContext.Result = new JsonResult { Data = new ReturnModel_Common { success = false, code = ReturnCode_Interface.服务端抛错, msg = filterContext.Exception.Message }, JsonRequestBehavior = JsonRequestBehavior.AllowGet }; } if (filterContext.Result is JsonResult) filterContext.ExceptionHandled = true;//返回结果是JsonResult，则设置异常已处理 else base.OnException(filterContext);//执行基类HandleErrorAttribute的逻辑，转向错误页面 }
异常过滤器就不像授权过滤器一样标注在方法上面了，直接到App_Start目录下的FilterConfig.cs注册下，这样所有的接口都可以生效了：
filters.Add(new LogExceptionAttribute());
异常过滤器里使用了NLog作为日志记录工具，Nuget安装命令：
Install-Package NLog Install-Package NLog.Config
相比Log4net，NLog配置简单，仅几行代码即可，NLog.config：
<?xml version="1.0" encoding="utf-8" ?> <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <targets> <target xsi:type="File" fileName="${basedir}/log/${shortdate}.log" layout="${uppercase:${level}} ${longdate} ${message}" /> <target xsi:type="File" fileName="D:\log\MVCExtension\${shortdate}.log" layout="${uppercase:${level}} ${longdate} ${message}" /> </targets> <rules> <logger minlevel="Debug" writeTo="f2" /> </rules> </nlog>
如果报错，日志就记录在D盘的log目录下的MVCExtension目录下，一个项目一个日志目录，方便管理。全部配置完成，看下代码：
public JsonResult HandleErrorFilterTest() { int i = int.Parse("abc"); return Json(new ReturnModel_Data { data = i }); }
字符串强转成int类型，必然报错，页面响应：
同时日志也记录下来了：
3.ActionFilter自定义过滤器
自定义过滤器就更加灵活了，可以精确的注入到请求前、请求中和请求后。继承抽象类ActionFilterAttribute并重写里面的方法即可：
public class SystemLogAttribute : ActionFilterAttribute { public string Operate { get; set; } public override void OnActionExecuted(ActionExecutedContext filterContext) { filterContext.HttpContext.Response.Write("<br/>" + Operate + "：OnActionExecuted"); base.OnActionExecuted(filterContext); } public override void OnActionExecuting(ActionExecutingContext filterContext) { filterContext.HttpContext.Response.Write("<br/>" + Operate + "：OnActionExecuting"); base.OnActionExecuting(filterContext); } public override void OnResultExecuted(ResultExecutedContext filterContext) { filterContext.HttpContext.Response.Write("<br/>" + Operate + "：OnResultExecuted"); base.OnResultExecuted(filterContext); } public override void OnResultExecuting(ResultExecutingContext filterContext) { filterContext.HttpContext.Response.Write("<br/>" + Operate + "：OnResultExecuting"); base.OnResultExecuting(filterContext); } }
这个过滤器适合做系统操作日志记录功能：
[SystemLog(Operate = "添加用户")] public string CustomerFilterTest() { Response.Write("<br/>Action 执行中..."); return "<br/>Action 执行结束"; }
看下结果：
四个方法执行顺序：OnActionExecuting—>OnActionExecuted—>OnResultExecuting—>OnResultExecuted，非常精确的控制了整个请求过程。