One person in household in Wuhan was allowed to go out once per week to the closest grocery store. And only allowed to go if no one in the apartment/house was COVID-19 positive or showing symptoms (in this case the government would deliver food and the door was nailed shut). In the grocery store only a tiny number of people were allowed in at your assigned appointment time. You had to keep roughly 50 feet away from other people in the store.
Wuhan and surrounding areas was the hotspot for the virus and had the majority of the cases. Other Chinese cities had minimal cases but also had mitigating measures including most workplaces being shutdown; they also had advance notice so they could do better preparation. These other cities in China had mitigating measures which included evicting people from the city who were considered high risk (take a look at all the recent stories about the mistreatment of people some Africa in China) and locking people in their homes if COVID-19 was suspected (as seen in many videos).
China has a new hotspot near the Russian border, Suifenhe, which is now locked down in the same manner as Wuhan.
Face masks did little to slow the disease in Wuhan or elsewhere in China. The government's lockdowns stopped COVID-19.