Guerrilla warfare in WW2 occupied Europe, was mainly sabotage actions where the Sten was carried as self defence, or to hold up guards protecting a factory, or a rail yard, while placing the explosives.
Direct encounters with German troops where mostly avoided, apart from the last days of the war, as far as I know.
The Danish resistance produced it’s own sten guns. Due to the simplicity of the design, any smith could make one, apart from the barrels. However, one raid on the rifle syndicate(rifle factory near Copenhagen), provided the Danish ressistance with hundreds of barrels.
Picture of a home made Sten

http://www.thm-online.dk/perioder/31/52/52-b2128/
