C# - NLog logs multiple lines for the same call

Question

I started using NLog and I want to log every line into a log file and a console for debugging purposes. When I try to log every single log action is printed 2-3 times in both console and the log file, instead of one time in each target.

I configured NLog in NLog.config file:

<?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>
    <target name="logfile" xsi:type="File" fileName="C:\Users\user\source\repos\TaskSchedulerConsole\Log.txt" />
    <target name="logconsole" xsi:type="Console" />
  </targets>

  <rules>
    <logger name="*" minlevel="Trace" writeTo="logfile, logconsole" />
    <logger name="*" minlevel="Debug" writeTo="logfile, logconsole" />
    <logger name="*" minlevel="Info" writeTo="logfile, logconsole" />
    <logger name="*" minlevel="Warn" writeTo="logfile, logconsole" />
    <logger name="*" minlevel="Error" writeTo="logfile, logconsole" />
    <logger name="*" minlevel="Fatal" writeTo="logfile, logconsole" />

  </rules>
</nlog>

In every class I created a static logger:

private static readonly NLog.Logger Logger = NLog.LogManager.GetCurrentClassLogger();

Example for triple logging: Program.cs:

            try
            {
                Logger.Info("Program Started.");

            }
            catch(Exception ex)
            {
                Logger.Info(ex, "Something went wrong...");
            }
            finally
            {
                Logger.Info("Program Finished.");
                NLog.LogManager.Shutdown();

            }

Output in both console and log file:

2020-05-14 11:49:44.7542|INFO|TaskSchedulerConsole.Program|Program Started.
2020-05-14 11:49:44.7542|INFO|TaskSchedulerConsole.Program|Program Started.
2020-05-14 11:49:44.7542|INFO|TaskSchedulerConsole.Program|Program Started.
2020-05-14 11:49:44.8315|INFO|TaskSchedulerConsole.Program|Program Finished.
2020-05-14 11:49:44.8315|INFO|TaskSchedulerConsole.Program|Program Finished.
2020-05-14 11:49:44.8315|INFO|TaskSchedulerConsole.Program|Program Finished.

Thanks in advance for everyone, hope someone can help me understand the problem.

If you remove <logger name="*" minlevel="Debug" writeTo="logfile, logconsole" /> <logger name="*" minlevel="Info" writeTo="logfile, logconsole" /> <logger name="*" minlevel="Warn" writeTo="logfile, logconsole" /> <logger name="*" minlevel="Error" writeTo="logfile, logconsole" /> <logger name="*" minlevel="Fatal" writeTo="logfile, logconsole" /> what happens? Why do you think that is? — mjwills

mehdi farhadi mehdi farhadi · Accepted Answer · 2020-05-14T09:15:01

1.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"
      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
      autoReload="true"
      throwExceptions="false"
      internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log">

  <variable name="myvar" value="myvalue"/>
  <targets>
     <target name="logfile" xsi:type="File" fileName="log-dest\Log.txt" />
     <target name="logconsole" xsi:type="Console" />
  </targets>

  <rules>
    <logger name="*" minlevel="Info" writeTo="logfile, logconsole" />       
  </rules>
</nlog>

2.program.cs

class Program
{
    private static readonly NLog.Logger Logger = NLog.LogManager.GetCurrentClassLogger();
    static void Main(string[] args)
    {
        try
        {
            Logger.Info("Program Started.");
        }
        catch (Exception ex)
        {
            Logger.Error(ex, "Something went wrong...");
        }
        finally
        {
            Logger.Info("Program Finished.");
            NLog.LogManager.Shutdown();
        }
    }
}

3.result

C# - NLog logs multiple lines for the same call

3 Answers