Asp.net mvc 筆記

捕捉處理全局異常

自定義一個Attribute繼承默認的HandleErrorAttribute

namespace EmpowerApiService.Filter
{
    public class CustomerErrorAttribute : HandleErrorAttribute
    {
        private static NLog.Logger logger = NLog.LogManager.GetCurrentClassLogger();

        public override void OnException(ExceptionContext filterContext)
        {
            if (filterContext.ExceptionHandled) { return; }


            var controllerName = (string)filterContext.RouteData.Values["controller"];
            var actionName = (string)filterContext.RouteData.Values["action"];
            var error = new { 
                message = filterContext.Exception.Message,
                hresult = filterContext.Exception.HResult.ToString("X")
            } ;

            if (filterContext.HttpContext != null && filterContext.HttpContext.Request != null)
            {
                var requestUrl = filterContext.HttpContext.Request.Url.ToString();
                var requestParams = filterContext.HttpContext.Request.Params;
                var requestParamsStr = HttpUtility.UrlDecode(requestParams.ToString());

                // 
                logger.Error(
                    filterContext.Exception,
                    "url: {0}, params: {1}",
                    new Object[] {requestUrl, requestParamsStr });
            }

            filterContext.ExceptionHandled = true;

            // request side error
            if (filterContext.Exception is ArgumentException)
            {
                filterContext.HttpContext.Response.StatusCode = 400;
            }
            // server side error
            else
            {
                filterContext.HttpContext.Response.StatusCode = 500;
            }
            // build http response
            filterContext.Result = new JsonResult() { ContentType = "applicaltion/json", ContentEncoding = System.Text.Encoding.UTF8, Data = error, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
        }
    }
}

註冊自定義的處理類，使之生效，替換默認的錯誤處理，修改APP_Start中的FilterConfig.cs

namespace EmpowerApiService
{
    public class FilterConfig
    {
        public static void RegisterGlobalFilters(GlobalFilterCollection filters)
        {
            //filters.Add(new HandleErrorAttribute());
            filters.Add(new EmpowerApiService.Filter.CustomerErrorAttribute());
        }
    }
}

在需要使用錯誤處理的Controller或Action上使用特性，就可以捕捉並處理異常

using EmpowerApiService.Filter;

namespace EmpowerApiService.Controllers{

   [CustomerError]
   public class xxxController : Controller{ ... }
}

使用日誌組件 NLog

先從Nuget安裝NLog，網文說要同時安裝NLog.Config，經實測不安裝也可以，測試版本是5.2.3
右鍵點擊目標項目，新增項，選擇新增配置文件，起名NLog.config

編輯文件如下

<?xml version="1.0"?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
	  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	  xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd"
	  autoReload="true"
	  throwException="false"
	  internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log">

	<variable name="appName" value="EmpowerApiService" />
	
	<targets>
		<target name="logfile" 
				xsi:type="File"
				fileName="${basedir}/logs/${appName}-${shortdate}.log"
				layout="${longdate}|${uppercase:${level}}|${message}${newline}${callsite}(${callsite-filename:includeSourcePath=False}:${callsite-linenumber})|${exception:format=ToString}"
				maxArchiveFiles="999"
				archiveFileName="${basedir}/logs/${appName}-${shortdate}-${###}.log"
				createDirs="true"
				archiveAboveSize="5242880"
				archiveEvery="Day"
				archiveNumbering="Sequence"
				encoding="UTF-8"
				>
		</target>
	</targets>

	<rules>
		<logger name="*" minlevel="Debug" writeTo="logfile"/>
	</rules>
</nlog>

在需要使用日誌的類中實例化日誌組件即可使用