The default approach for managing Loggers via the global singletonLogManager class in NLog. It works well for homogeneous applications where the main application and all the extension components are configured via a single configuration file.

By including the component class-namespace in the Logger-name (Happens automatically when usingNLog.LogManager.GetCurrentClassLogger()), then it is easy to configure NLog Logging-Rules to route to the wanted destination-target for the plugin (Ex.filename="Plugin-${logger}.log").

If the component is complex and uses many Logger-instances, then one can consider to also imbue the component Logger-instance with a common LogEvent-PropertyName:

varpluginLogger=NLog.LogManager.GetLogger(componentName).WithProperty("ComponentName",componentName);

Then it is possible to include the component-identifier in the target output. Ex${event-properties:ComponentName:whenEmpty=Core}

See also${event-properties}

But sometimes you want to create a separate logging configuration, just for a particular component, plugin or extension. Instead of usingLogManager (which is global to an application) then one can use isolatedLogFactory object-instance that is local to your component/plugin. It allows you to have multipleLogFactory-instances, where each have their own isolated logging configuration.

When creatingLogFactory you need to explicitly pass the configuration (either from a file or by programmatically constructing targets and rules) as in the following example:

internalclassMyLogManager{// A Logger dispenser for the current assembly (Remember to call Flush on application exit)publicstaticLogFactoryInstance{get{return_instance.Value;}}privatestaticLazy<LogFactory>_instance=newLazy<LogFactory>(BuildLogFactory);//// Use a config file located next to our current assembly dll// eg, if the running assembly is c:\path\to\MyComponent.dll// the config filepath will be c:\path\to\MyComponent.nlog//// WARNING: This will not be appropriate for assemblies in the GAC//privatestaticLogFactoryBuildLogFactory(){// Use name of current assembly to construct NLog config filenameAssemblythisAssembly=Assembly.GetExecutingAssembly();stringconfigFilePath=Path.ChangeExtension(thisAssembly.Location,".nlog");LogFactorylogFactory=newLogFactory();logFactory.Configuration=newXmlLoggingConfiguration(configFilePath,true,logFactory);returnlogFactory;}}

Then all you need to do is to create loggers with:

Loggerlogger=MyLogManager.Instance.GetLogger("name");

or

Loggerlogger=MyLogManager.Instance.GetCurrentClassLogger();

If you want multiple assemblies to share thisMyLogManager – just make it a public class and get others to use it.

NLog LogFactory will attempt to automatically shutdown together with the AppDomain / ProcessExit. But it is recommended to shutdown the isolate LogFactory in the plugin-dispose-stage by callingLogFactory.Shutdown().

See Also:Explicit NLog configuration loading