Question

I’m trying to understand the difference between OnStart() and the constructor in a ServiceBase derived class. From reading around it seems that the first time you start a service (after turning on your machine), the constructor is called. Thereafter, you can stop and start the service as many times as you like, but the constructor will never be called again, only the OnStart() method will be called each time. Can anyone confirm?

Thanks

Answer 1

Do not use the constructor to perform processing that should be in OnStart. Use OnStart to handle all initialization of your service. The constructor is called when the application’s executable runs, not when the service runs. The executable runs before OnStart. When you continue, for example, the constructor is not called again because the SCM already holds the object in memory. If OnStop releases resources allocated in the constructor rather than in OnStart, the needed resources would not be created again the second time the service is called.
MSDN