c# - Save Settings in Dependent Dll -

i have windows service , dependent dll, chose way dll can invoked application, winforms, wpf etc.

now stumped on best practice save settings in dll, used user settings in dll , saved them calling app.

public class preferences {     public static string ipaddress     {         { return settings.default.ipaddress; }         set { settings.default.ipaddress = value; }     } } 

and in service/winforms code, wrote

preferences.ipaddress = "xx.xx.xx.xx" 

someone told me not how should . wanted know not correct approach