Q.How can I stop woodlice eating my ripe strawberries?
I have put straw down to stop the slugs, which seems to work, but when I come to pick a ripe strawberry, it has woodlice biting into it.

Rake up and remove any mulch in or near your Strawberry bed.
Introduce beneficial Toads to the garden.
As a natural way of eliminating woodlice, you can also use Diatomaceous Earth and boric acid for the same result, as both are natural based products which have the effect of dehydrating the insects once they come in contact with the substance.
https://www.gardeningknowhow.com/edible/fruits/strawberry/protecting-strawberries-from-insects.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/diatomaceous-earth-insect-control.htm