Setting up dynamic connection string for log4net

问题

I am using log4net and I am have a connection string I want to reference in my log4net config, because the connectionString in "/Config/connectionStrings.config" will be dynamic input from the user.

Here is what I am trying to do:

 <log4net xmlns="log4net">
    <root>
     <level value="ERROR" />
     <appender-ref ref="DatabaseAppender" />
   </root>

<appender name="DatabaseAppender" type="log4net.Appender.AdoNetAppender">
  <bufferSize value="100" />
  <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  <connectionStrings configSource="Config\ConnectionStrings.config" />
  <commandText value="INSERT INTO dm.ErrorLogs ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
  <parameter>....
 </appender>
 </log4net>

Log4net expects something like this in the connectionStrings:

<connectionString value="data source=SQLSVR;initial catalog=test_log4net;integrated security=false;persist security info=True;User ID=sa;Password=sa" />

My reference config: Config\ConnectionStrings.config All of which is input from the user, so I need the connectionString value of the second connectionString attribute which is

"Data Source=(local);Initial Catalog=DbTwo;Integrated Security=True;MultipleActiveResultSets=True;Application Name=AppName2".

Is there a way to get this value using ASP.NET C#, so I can create a database appender in code? Or is there another I cold do this in the log4net.config?

   <connectionStrings>
   <add name="Connection1" 
    connectionString="Data Source=(local);Initial Catalog=DbOne;Integrated Security=True;Application Name=AppName1" 
     providerName="System.Data.SqlClient" />
   <add name="Connection2" 
     connectionString="Data Source=(local);Initial Catalog=DbTwo;Integrated Security=True;MultipleActiveResultSets=True;Application Name=AppName2" 
     providerName="System.Data.SqlClient" />

回答1:

Code looks like this:

 //connectionString is the Web.config's connectionString, which I wanted to share.
 public static void SetUpDbConnection(string connectionString, string logConfig)
    {
        //update connection string for log4net dynamically
        var hier = LogManager.GetRepository() as Hierarchy;
        log4net.Config.XmlConfigurator.ConfigureAndWatch(new FileInfo(logConfig));
        if (hier != null)
        {
            var adoNetAppenders = hier.GetAppenders().OfType<AdoNetAppender>();
            foreach (var adoNetAppender in adoNetAppenders)
            {
                adoNetAppender.ConnectionString = connectionString;
                adoNetAppender.ActivateOptions();
            }
        }
    }

来源：https://stackoverflow.com/questions/18112762/setting-up-dynamic-connection-string-for-log4net

标签

xml

c#-4.0

configuration

web-config

log4net