There is no law about "open containers" if that's what you mean. As for "approving smiles", those were almost surely astonishment smiles or "What a nutty foreigner" smiles. You will notice that in all cities in China, NO CHINESE EVER drinks in public, such as a park bench, except the occasional derelict. Along some low-rent alleyways, you will sometimes see a few 30 or 40-something men drinking beer in "lawn" chairs, but they do not walk down the street while drinking from a bottle. If you have any sense of fitting in, restrict your booze to restaurant, bar, or home.
