UIImageView怎么设置点击事件ios,swift?

Question

let tapStepGestureRecognizer = UITapGestureRecognizer(target: self, action: Selector("enterStepDetail"))stepLogo.addGestureRecognizer(tapStepGestureRecognizer) func enterStepDetail(){    print("step detail ok") }//我现在的代码，但是下面的方法不执行。