log4net：ERROR ConfigureFromXml 使用 null 'element' 参数调用

Question

我们使用的log4net库带有.net core来在文件中编写日志。但是，在执行应用程序" log4net：错误配置fromxml(时，我们会遇到此错误。这是我们的program.cs文件：

public class Program
{
    public static void Main(string[] args)
    {
        XmlDocument log4netConfig = new XmlDocument();
        log4netConfig.Load(File.OpenRead("log4net.config"));
        var repo = log4net.LogManager.CreateRepository(Assembly.GetEntryAssembly(), typeof(log4net.Repository.Hierarchy.Hierarchy));
        log4net.Config.XmlConfigurator.Configure(repo, log4netConfig["log4net"]);
        BuildWebHost(args).Run();
    }
    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();
}

这是startup.cs文件中的配置方法：

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        loggerFactory.AddConsole(LogLevel.Trace);
        loggerFactory.AddLog4Net();
        app.UseIdentityServer();
    }

这是log4net.config文件：

    <?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=1b44e1d426115821" />
  </configSections>
  <!-- Log4net Logging Setup -->
  <log4net>
    <appender name="FileAppender" type="log4net.Appender.FileAppender,log4net">
      <file value="c:LogFilesApplicationsIdentityServerlog.txt" />
      <appendToFile value="true" />
      <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %level %logger - %message%newline" />
      </layout>
      <filter type="log4net.Filter.LevelRangeFilter">
        <levelMin value="INFO" />
        <levelMax value="FATAL" />
      </filter>
    </appender>
    <root>
      <level value="DEBUG"/>
      <appender-ref ref="FileAppender"/>
    </root>
  </log4net>
</configuration>

Answer 1

用以下代码替换log4net.config：

    <?xml version="1.0" encoding="utf-8" ?>
<log4net>
  <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
    <lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
    <file value="C:Temp" />
    <datePattern value="yyyy-MM-dd.'txt'"/>
    <staticLogFileName value="false"/>
    <appendToFile value="true"/>
    <rollingStyle value="Date"/>
    <maxSizeRollBackups value="100"/>
    <maximumFileSize value="15MB"/>
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level App  %newline %message %newline %newline"/>
    </layout>
  </appender>
  <root>
    <level value="ALL"/>
    <appender-ref ref="RollingLogFileAppender"/>
  </root>
</log4net>

Answer 2

实际上，接受的响应不准确，XML的问题是Log4NET配置顶部的.NET配置。原始配置文件是.NET配置文件而不是log4net文件，它与 configuration node植根于 log4net node。

。

另一方面，第二个配置XML是正确的，但是它替换了原始配置(也许可以用更好的配置(，不仅可以解决问题，还可以用新的配置代替原始配置。

更改的更好响应将是：

1. configuration root节点从原始XML文件和 configSections node一起，然后将log4Nnet节点作为XML的根，从而在：

   <?xml version="1.0" encoding="utf-8" ?>
   <!-- Log4net Logging Setup -->
   <log4net>
     <appender name="FileAppender" type="log4net.Appender.FileAppender,log4net">
       <file value="c:LogFilesApplicationsIdentityServerlog.txt" />
       <appendToFile value="true" />
       <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
       <layout type="log4net.Layout.PatternLayout">
         <conversionPattern value="%date [%thread] %level %logger - %message%newline" />
       </layout>
       <filter type="log4net.Filter.LevelRangeFilter">
         <levelMin value="INFO" />
         <levelMax value="FATAL" />
       </filter>
     </appender>
     <root>
       <level value="DEBUG"/>
       <appender-ref ref="FileAppender"/>
     </root>
   </log4net>
   

如果需要