C# NLog Helper类（c#是什么语言）

安装

通过Nuget安装，搜索Nlog, 然后安装NLog和NLog.Config（相当于一个配置模板）。

当然也可以自己在项目根目录下创建一个配置文件NLog.config，注意在NLog.config的属性中设置 Copy to Output Directory: Copy always

public class LogHelper
    {
        private static readonly Logger log = LogManager.GetLogger(string.Empty);

        public static void Trace(object msg, Exception ex = null)
        {
            if (ex == null)
            {
                log.Trace(msg.ParseToString());
            }
            else
            {
                log.Trace(msg + GetExceptionMessage(ex));
            }
        }

        public static void Debug(object msg, Exception ex = null)
        {
            if (ex == null)
            {
                log.Debug(msg.ParseToString());
            }
            else
            {
                log.Debug(msg + GetExceptionMessage(ex));
            }
        }

        public static void Info(object msg, Exception ex = null)
        {
            if (ex == null)
            {
                log.Info(msg.ParseToString());
            }
            else
            {
                log.Info(msg + GetExceptionMessage(ex));
            }
        }

        public static void Warn(object msg, Exception ex = null)
        {
            if (ex == null)
            {
                log.Warn(msg.ParseToString());
            }
            else
            {
                log.Warn(msg + GetExceptionMessage(ex));
            }
        }

        public static void Error(object msg, Exception ex = null)
        {
            if (ex == null)
            {
                log.Error(msg.ParseToString());
            }
            else
            {
                log.Error(msg + GetExceptionMessage(ex));
            }
        }

        public static void Error(Exception ex)
        {
            if (ex != null)
            {
                log.Error(GetExceptionMessage(ex));
            }
        }

        public static void Fatal(object msg, Exception ex = null)
        {
            if (ex == null)
            {
                log.Fatal(msg.ParseToString());
            }
            else
            {
                log.Fatal(msg + GetExceptionMessage(ex));
            }
        }

        public static void Fatal(Exception ex)
        {
            if (ex != null)
            {
                log.Fatal(GetExceptionMessage(ex));
            }
        }

        private static string GetExceptionMessage(Exception ex)
        {
            string message = string.Empty;
            if (ex != null)
            {
                message += ex.Message;
                message += Environment.NewLine;
                Exception originalException = ex.GetOriginalException();
                if (originalException != null)
                {
                    if (originalException.Message != ex.Message)
                    {
                        message += originalException.Message;
                        message += Environment.NewLine;
                    }
                }
                message += ex.StackTrace;
                message += Environment.NewLine;
            }
            return message;
        }

级别由低到高

• Trace 记录完整的信息，一般只用在开发环境
• Debug 记录调试信息，没有Trace信息完整，一般也只用在开发环境
• Info 简单的信息，一般用在生产环境
• Warn 记录警告信息，一些可以解决的小问题
• Error 记录报错信息，一般都是Exceptions信息
• Fatal 非常严重的错误信息

一个简单的配制文件

<?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"
      autoReload="true"
      internalLogLevel="Off"
      throwExceptions="false">


  <!-- the targets to write to -->
  <targets>
    <!-- write logs to file  -->
    <target xsi:type="File" name="all" fileName="${basedir}/logs/${shortdate}.log"
            layout="${longdate}|${message} ${exception:format=tostring}" />
  </targets>

  <!-- rules to map from logger name to target -->
  <rules>
    <logger name="*" minlevel="Trace" writeTo="all" />
  </rules>
</nlog>

调用方法

LogHelper.Info("启动");