let lable1 = UILabel(frame: CGRect(x: CGFloat(self.view.bounds.width/2-20), y: CGFloat(history.frame.origin.x + 12), 390.0, height: 24.0))
lable1.adjustsFontSizeToFitWidth = true
lable1.text = "课程"
lable1.font = UIFont.systemFontOfSize(19.0) //设置字体大小
self.view.addSubview(lable1)