  Allaying Hunger with Pictures of Cakes 画饼充饥

  In the Three Kingdoms Period (220-280), the king of the Wei, Cao Rui, wanted to select a very capable man to work for him. He said to his ministers: 'When choosing a talented person, always beware of one with a false reputation. A false reputation is just like a picture of a cake; it can' t relieve hunger.' 
  三国时代魏国的皇帝曹睿，准备选拔一个有才能的人到朝廷来做官。曹睿对他的大臣说："选择人才，不能光找有虚名的人。虚名好像是在地上画的一块饼，只能看，不能解决肚子饥饿的问题啊！" 

  Later, this idiom came to be used to mean comforting oneself with unrealistic thoughts, without solving practical problems.
  后来人们就用"画饼充饥"这个成语比喻用空想安慰自己，不能解决实际问题。