c# - 带有 AdoNetAppender 的 Log4Net - 没有任何反应

Question

描述

我的程序集中有一个配置文件作为资源，我想在我的应用程序中以编程方式更改 ConnectionString。

我使用 log4net.Config.XmlConfigurator.Configure 加载配置.

我有一些断点，看到配置加载成功，连接字符串为 Data Source=localhost\SQLExpress;Initial Catalog=Log;Integrated Security=SSPI; (本地 SQLExpress)。

问题

没有任何反应，没有异常，也没有日志条目。任何想法。

using (Stream stream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("MyNamespace.Properties.log4net.config"))
{ 
    // stream is NOT null
    log4net.Config.XmlConfigurator.Configure(stream);
}

Hierarchy hier = LogManager.GetRepository() as Hierarchy;

if (hier != null)
{
    //get ADONetAppender
    var adoAppender = (AdoNetAppender)hier.GetAppenders().Where(appender => appender.Name.Equals("AdoNetAppender", StringComparison.InvariantCultureIgnoreCase)).FirstOrDefault();

    if (adoAppender != null)
    {
        // update connectionstring
        adoAppender.ConnectionString = configuration.GetConnectionString(ConnectionStringNames.Log).ConnectionString;
        //refresh settings of appender
        adoAppender.ActivateOptions(); 
    }
}

ILog logger = LogManager.GetLogger("MyProject"); 
logger.Warn("Test");

log4net.config 文件的内容

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
  </configSections>

  <log4net>
    <appender name="AdoNetAppender" type="log4net.Appender.ADONetAppender">
      <bufferSize value="1" />
      <connectionType value="System.Data.SqlClient.SqlConnection, System.Data,
  Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
      <connectionString value="[we will set this automatically at runtime]" />
      <commandText value="INSERT INTO Log ([Date],[Level],[Logger],[Message],[Exception])
  VALUES (@log_date, @log_level, @logger, @message, @exception)" />
      <parameter>
        <parameterName value="@log_date" />
        <dbType value="DateTime" />
        <layout type="log4net.Layout.RawTimeStampLayout" />
      </parameter>
      <parameter>
        <parameterName value="@log_level" />
        <dbType value="String" />
        <size value="50" />
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%p" />
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@logger" />
        <dbType value="String" />
        <size value="255" />
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%c" />
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@message" />
        <dbType value="String" />
        <size value="4000" />
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%m" />
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@exception" />
        <dbType value="String" />
        <size value="2000" />
        <layout type="log4net.Layout.ExceptionLayout" />
      </parameter>
    </appender>

    <root>
      <level value="ALL" />
      <appender-ref ref="AdoNetAppender" />
    </root>
  </log4net>
</configuration>

Answer 1

您可以通过挂接到 log4net DebugAppender 来调试 log4net:

在您的 app.config 文件中添加 log4net 应用程序设置:

<appSettings>
  <!-- log4net configuration when running in debug mode. -->    
  <add key="log4net.Internal.Debug" value="true" />   
</appSettings>

在 log4net 配置中添加调试附加程序:

<appender name="DebugAppender" type="log4net.Appender.DebugAppender">
  <immediateFlush value="true" />
  <layout type="log4net.Layout.SimpleLayout" />
</appender>

将 appender 添加到 log4net 配置根:

<root>
  <level value="ALL" />
  <appender-ref ref="AdoNetAppender" />
  <appender-ref ref="DebugAppender" />
</root>

当您运行应用程序时，查看 Visual Studio 的输出窗口，您应该会看到 log4net 的所有内部日志记录。如果不是，则永远不会加载 log4net 配置文件。

编辑

如果您可以使用 app.config 文件中的连接字符串，则从 log4net AdoNetAppender 中删除连接字符串并按名称调用连接字符串:

<appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
  <bufferSize value="1" />
  <!-- note: you can use the 4.0 assembly -->
  <connectionType value="System.Data.SqlClient.SqlConnection,
              System.Data, 
              Version=4.0.0.0, 
              Culture=neutral, 
              PublicKeyToken=b77a5c561934e089" />
  <!-- This will retrieve a connection string by name from the app.config -->
  <connectionStringName value="ConnectionStringNameFromAppConfig" />
  <!-- snip -->
</appender>