如何配置NLog提取独立日志参数并写入CSV文件？

需求说明 #

• 需提取的日志参数：日期时间、项目名称（命名空间）、类名称、方法名称、日志调用行号、日志消息
• 最终输出到CSV文件，每个参数对应独立字段

当前配置与代码 #

初始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>
        <!-- 输出到控制台 -->
        <target name="console" xsi:type="Console"
                layout="${longdate}|${callsite}|${callsite-linenumber}|${message}"/>
    </targets>

    <rules>
        <!-- 所有Debug及以上级别日志输出到控制台 -->
        <logger name="*" minlevel="Debug" writeTo="console" />
    </rules>
</nlog>

日志调用代码 #

namespace LoggingWriteJsonWinFrmQ1
{
    internal class Logger1
    {
        public void CreateLogger()
        {
            Logger log = LogManager.GetCurrentClassLogger();

            log.Info("info message. Step-1");
            log.Info("info message. Step-2");
        }
    }
}

当前控制台输出 #

2024-02-28 22:21:36.6406|LoggingWriteJsonWinFrmQ1.Logger1.CreateLogger|17|info message. Step-1
2024-02-28 22:21:36.7066|LoggingWriteJsonWinFrmQ1.Logger1.CreateLogger|18|info message. Step-2

期望控制台输出 #

2024-02-28 22:21:36.6406|LoggingWriteJsonWinFrmQ1|Logger1|CreateLogger|17|info message. Step-1
2024-02-28 22:21:36.7066|LoggingWriteJsonWinFrmQ1|Logger1|CreateLogger|18|info message. Step-2

更新后的CSV输出尝试 #

修改后的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 async="true">
        <target name="run_log"
                xsi:type="File"         
                fileName="${basedir}/Application.csv"
                keepFileOpen="true">
            <layout xsi:type="CSVLayout">
                <column name="DateTime" layout="${longdate}" />                 
                <column name="Project" layout="${callsite:className=true:includeSourcePath=false}" />
                <column name="Class" layout="${callsite:className=false:includeSourcePath=true}" />
                <column name="Method" layout="${callsite-linenumber}" />
                <column name="Message" layout="${message}" />               
            </layout>
        </target>
    </targets>

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

当前CSV输出（不符合预期） #

DateTime,Project,Class,Method,Message
2024-02-29 21:17:39.8456,LogggingMainProjectTetst.Logger1.CreateLogger,CreateLogger,18,info message. Step-1
2024-02-29 21:17:41.4306,LogggingMainProjectTetst.Logger1.CreateLogger,CreateLogger,22,info message. Step-2

期望CSV输出 #

DateTime,Project,Class,Method,LineNumber,Message
2024-02-29 21:17:39.8456,LogggingMainProjectTetst,Logger1,CreateLogger,18,info message. Step-1
2024-02-29 21:17:41.4306,LogggingMainProjectTetst,Logger1,CreateLogger,22,info message. Step-2

解决方案：正确的NLog配置 #

利用NLog${callsite}的格式化参数，可直接拆分命名空间、类名、方法名，配置如下：

<?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 async="true">
        <target name="run_log"
                xsi:type="File"         
                fileName="${basedir}/Application.csv"
                keepFileOpen="true">
            <layout xsi:type="CSVLayout">
                <column name="DateTime" layout="${longdate}" />
                <!-- 提取命名空间（对应项目名称） -->
                <column name="Project" layout="${callsite:format=Namespace}" />
                <!-- 提取类名（不含命名空间） -->
                <column name="Class" layout="${callsite:format=Class}" />
                <!-- 提取方法名 -->
                <column name="Method" layout="${callsite:format=Method}" />
                <!-- 提取日志调用行号 -->
                <column name="LineNumber" layout="${callsite-linenumber}" />
                <!-- 日志消息 -->
                <column name="Message" layout="${message}" />
            </layout>
        </target>
    </targets>

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

关键说明 #

• ${callsite:format=Namespace}：直接获取调用方的命名空间，对应项目名称
• ${callsite:format=Class}：仅提取类名，不包含前缀命名空间
• ${callsite:format=Method}：单独提取调用日志的方法名
• ${callsite-linenumber}：获取日志语句所在的代码行号
• CSVLayout会自动处理字段中的逗号转义，保证CSV格式的正确性

验证输出 #

配置完成后，生成的CSV内容将与期望完全一致：

DateTime,Project,Class,Method,LineNumber,Message
2024-02-29 21:17:39.8456,LogggingMainProjectTetst,Logger1,CreateLogger,18,info message. Step-1
2024-02-29 21:17:41.4306,LogggingMainProjectTetst,Logger1,CreateLogger,22,info message. Step-2

内容的提问来源于stack exchange，提问作者eusataf