如何编写c＃服务，我也可以作为winforms程序运行？

I have a windows service written in C# that acts as a proxy for a bunch of network devices to the back end database. For testing and also to add a simulation layer to test the back end I would like to have a GUI for the test operator to be able run the simulation. Also for a striped down version to send out as a demo. The GUI and service do not have to run at the same time. What is the best way to achieve this duel operation?I have a windows service written in C# that act