见风使帆

jiànfēng-shǐfān

[trim one's sails; sail with the wind; see how the gander hops; watch how the cat jumps; go with the crowd; sail with the current (stream, tide, times)] 根据风向使用帆位。 比喻见机而行, 灵活变通

别事见风使帆, 再作道理。 --《官场现形记》