System.ComponentModel.Design.ServiceCreatorCallback provides a mechanism to publish services that you can request to have created when needed, rather than the service being created immediately when the designer loads. You can use a callback function if the service is not essential and may not be used. A service published by using a System.ComponentModel.Design.ServiceCreatorCallback does not use as many additional resources if it is not requested and created. To use a callback function to publish your service, pass a System.ComponentModel.Design.ServiceCreatorCallback to the IServiceContainer.AddService(Type, object) method of an System.ComponentModel.Design.IServiceContainer.