首先配置log4net Entity Framework数据库

Question

I am trying to implement log4net in a project using Entity Framework 6.0 with a database-first approach. I can log to a file and I could create a separate connection string using ADO but I want to use the Entity Framework context. Does anyone know of any websites offering information on how to achieve this?

Here is my current config to log to a file:

<configSections> 
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<log4net>
    <appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
      <param name="File" value="c:\logs\webAApp.log"/>
      <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
      <appendToFile value="true" />
      <rollingStyle value="Size" />
      <maxSizeRollBackups value="2" />
      <maximumFileSize value="1MB" />
      <staticLogFileName value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d [%t] %-5p %c %m%n"/>
      </layout>
    </appender>
    <root>
      <level value="ALL" />
      <appender-ref ref="LogFileAppender" />
    </root>
</log4net>

Here's my new configuration:

<configSections>
<section name="log4net" ype="log4net.Config.Log4NetConfigurationSectionHandler,Log4net"/>
  </configSections>
  <log4net>
    <root>
      <level value="DEBUG" />
      <appender-ref ref="ADONetAppender" />
    </root>
    <appender name="ADONetAppender" type="log4net.Appender.ADONetAppender">
      <bufferSize value="1" />
      <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
      <connectionString value="server=pcrcrm.database.windows.net; uid=pcrdevadmin; pwd=Priv@te1; database=CRM-dev" />
      <commandText value="INSERT INTO [dbo].[ERROR_LOGGING] ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
      <parameter>
        <parameterName value="@log_date"/>
        <dbType value="DateTime"/>
        <layout type="log4net.Layout.RawTimeStampLayout"/>
      </parameter>
      <parameter>
        <parameterName value="@thread"/>
        <dbType value="String"/>
        <size value="255"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%thread"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@log_level"/>
        <dbType value="String"/>
        <size value="50"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%level"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@logger"/>
        <dbType value="String"/>
        <size value="255"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%logger"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@message"/>
        <dbType value="String"/>
        <size value="4000"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%message"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="@exception"/>
        <dbType value="String"/>
        <size value="2000"/>
        <layout type="log4net.Layout.ExceptionLayout"/>
      </parameter>
    </appender>
  </log4net>

Answer 1

This is how you can do it

static void Main()
{
     XmlConfigurator.Configure();
     SetupLog4Net();
}

private static void SetupLog4Net()
{
    Hierarchy hierarchy = LogManager.GetRepository() as Hierarchy;
    if(hierarchy != null && hierarchy.Configured)
    {
        foreach(IAppender appender in hierarchy.GetAppenders())
        {
           if(appender is AdoNetAppender)
           {
               var adoNetAppender = (AdoNetAppender)appender;
               adoNetAppender.ConnectionString = dbContext.Database.Connection.ConnectionString;
               adoNetAppender.ActivateOptions();
           }
        }
    }
}

Hope this helps.

Answer 2

First, create a log class.

public class DatabaseLogger
{
    readonly static log4net.ILog logger = log4net.LogManager.GetLogger("ADONetAppender");

    public static void LogDebug(string message)
    {
        logger.Debug(message);
    }
}

Create a new context class that inherits from the EF Context and inside the constructor set the property on the database log to an instance of the debugger class above.

public partial class InheritedContext : DbContext
{
    public InheritedContext() :
        base("DatabaseConnectionString")
    {
        Database.Log = DatabaseLogger.LogDebug;
        this.Configuration.LazyLoadingEnabled = false;
    }