UIScrollView宽度和高度控件

Question

Here is how I create and initialise my UIScrollView :

class MyViewController: UIViewController, UIScrollViewDelegate{

    let items = 20, heightPerItem: CGFloat = 40;
    var scrollView: UIScrollView!
    var contentView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        scrollView = UIScrollView(frame: view.bounds)
        contentView = UIView(frame: view.bounds)

        scrollView.backgroundColor = UIColor.blackColor()
        scrollView.autoresizingMask = UIViewAutoresizing.FlexibleHeight

        var yStart: CGFloat = 0 - heightPerItem
        for i in 0 ..< items {
            yStart += heightPerItem
            let label = UILabel(frame: CGRect(x: 0, y: yStart, width: self.view.bounds.size.width, height: heightPerItem - 1))
            label.text = "\(i) testing..."
            label.backgroundColor = UIColor.brownColor()
            scrollView.addSubview(label)
        }

        view.addSubview(scrollView)
    }

    override func viewDidLayoutSubviews() {
        scrollView.addSubview(contentView)
        scrollView.contentSize.height = heightPerItem * CGFloat(items)
    }
}

And here is the output:

It could be ok if I never tried orientation change:

So, please look at the following two points:

1. Is there any other way the scrollView gets height automatically (at least I don't want to do scrollView.contentSize.height = heightPerItem * CGFloat(items) )?
2. How to re-write the code so that the width of the scrollView gets changed just with orientation change?

Answer 1

I made small changes in your code and placed

scrollView.autoresizingMask = [UIViewAutoresizing.FlexibleHeight, .FlexibleWidth]

and

let label = UILabel(frame: CGRect(x: 0, y: yStart, width: self.view.bounds.size.height, height: heightPerItem - 1))

it solved the issue of width in landscape.

If you want to control size changes when orientation changes, you can override func viewWillTransitionToSize, for example:

    override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {

    if UIDevice.currentDevice().orientation.isLandscape {
        print("Landscape")
    } else {
        print("Portrait")
    }


}

In addition, for part 1. AFAIK, UIScrollView does not have property that will take maximum of y coordinate, but we can make a small code like this:

    func rectMax() -> CGRect {
       var cR = CGRectZero
       for sv in scrollView.subviews {
           cR = CGRectUnion(cR, sv.frame)
       }

    return cR
}

and than you can use:

        scrollView.contentSize = rectMax().size