如何在PageViewController swift中缩放ImageView

Question

我正在使用加载多张图片的PageViewController。我可以逐个浏览图像。我现在想要缩放ImageView，我该如何实现它。提前谢谢。

我在 viewDidLoad

中有这个

var vWidth = self.view.frame.width
var vHeight = self.view.frame.height

var scrollImg: UIScrollView = UIScrollView()
scrollImg.delegate = self
scrollImg.frame = CGRectMake(0, 0, vWidth, vHeight)
scrollImg.backgroundColor = UIColor(red: 90, green: 90, blue: 90, alpha: 0.90)
scrollImg.alwaysBounceVertical = false
scrollImg.alwaysBounceHorizontal = false
scrollImg.showsVerticalScrollIndicator = true
scrollImg.flashScrollIndicators()

scrollImg.minimumZoomScale = 1.0
scrollImg.maximumZoomScale = 10.0

self.view.addSubview(scrollImg)

scrollImg.addSubview(contentImageView!)

然后是 scrollview

的代表

func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
        return self.contentImageView
    }

现在图像变得异常变焦，主要集中在顶部。而且无法平息它。