Assembly: System.ServiceProcess (in system.serviceprocess.dll)
The constructor initializes the EventLog property to an instance with the EventLog.Source and EventLog.Log properties set. The source is the ServiceName of the service, and the log is the computer's Application log. These values are set automatically and cannot be changed for automatic logging of service commands.
When AutoLog is true, Start, Stop, Pause, Continue, and custom commands are recorded automatically in the Application event log. You can use the EventLog property to write additional messages to that log as well. The component calls EventLog.WriteEntry using this EventLog member.
If you want to write entries to an event log other than the application log, set AutoLog to false, instantiate a new EventLog in the constructor for your service component, and override the OnStart, OnStop, and other command-handling methods to explicitly post entries to that log. You cannot use this EventLog instance to write to logs other than the Application log.