2018-05-22如何使下划线view的宽度等于button控

问题描述:如何使下划线view的宽度等于button控件的宽度?

Snip20180522_1.png

1.想这个默认选择第一个的时候,下划线的宽度要在选中之后进行设置,不能在刚开始的设置好frame

2.代码如下:

private func selectedButton(_ button:UIButton) {
        
        let x: CGFloat = button.frame.origin.x
        selectedunderLine.frame.origin.x = x
        
        if button.tag == 0{
            selectedunderLine.width = titleList[button.tag].getSize(14).width

        }else{
            selectedunderLine.width = titleList[button.tag].getSize(size: button.size, 14.scaleValue).width
        }
        
        selectButton.isSelected = false
        button.isSelected = true
        selectButton = button
        
    }

3.运行图如下:

Snip20180522_3.png