ios - 分段控制，改变色调不透明度，但不改变边框

Question

在 Swift 中，如何更改所选索引的色调不透明度，而不是整个控件的边框？

这会改变整个控件的颜色和不透明度:

sessionTypeSegmentedControl.tintColor = UIColor(red: 140/255, green: 140/255, blue: 140/255, alpha: 0.1)

接着是我试过的:

sessionTypeSegmentedControl.layer.borderColor = UIColor(red: 0/255, green: 0/255, blue: 0/255, alpha: 1.0).cgColor

但这对边界没有影响。

编辑:

我想更改此图像中显示的蓝色背景颜色的不透明度。在最左边。

http://i.stack.imgur.com/GgUwN.png

所以预期的结果是:

http://imgur.com/a/AIRhO

Answer 1

我找到了这个解决方案...Swift 3 Xcode 8

    @IBAction func valueChanged(_ sender: UISegmentedControl) {

    for (index,element) in segment.subviews.enumerated() {

        if index != sender.selectedSegmentIndex {
            element.tintColor = UIColor.red
            element.alpha = 0.5
        }else {

            element.tintColor = UIColor.red
            element.alpha = 1

        }
    }



}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    for (index,element) in segment.subviews.enumerated() {

        if index != segment.selectedSegmentIndex {
            element.tintColor = UIColor.red
            element.alpha = 0.5
        }else {

            element.tintColor = UIColor.red
            element.alpha = 1

        }
    }

            segment.layer.cornerRadius = 5
            segment.layer.borderColor = UIColor.black.cgColor
            segment.layer.borderWidth = 1
            segment.clipsToBounds = true



}