这个是表达“做什么事怎么样呢?”之意,主要是用来提出建议,征得赞同. Ex：what about/how about having sth.to eat (吃点东西好吗?) what about/how about seeing a film （去看电影好吗?） PS:what about/how about + 名词. Ex：what about/how about my suggestion (我的建议怎样呢?) what about/how about this photo （这张照片怎么样?） I hope my answer will be useful for U .
