比喻用一种假象迷惑对方，实际上却另有打算。
fig. to feign one thing while doing another; to cheat under cover of a persion; lit. repair the plank road by day while secretly crossing the Wei River 渭河at Chencang (idiom, refers to a stratagem used by Liu Bang 刘邦in 206 BC against Xiang Yu 项羽of Chu)
