AutoLayout调整自定义UIView内容的大小

Question

I have a standard UIView added via IB which changes size based on orientation using constraints. Programatically I add a custom component (sub-classing UIView) to this view which by default is the sam size as its parent view. Problem is, how do I get my custom view (programatically added) to update its size based to match its parent when the parents size changes (due to orientation change)?

@IBOutlet weak var cardView: UIView!
override func viewDidLoad() {
    super.viewDidLoad()

    let frame = cardView.bounds
    // Custom component sub classes UI View
    // Should always be same size as its parent
    let imageTemplateView: ImageTemplateView = ImageTemplateView(frame: frame)

    cardView.addSubview(imageTemplateView)
}

Answer 1

Set your programmatically added view's top,bottom,leading and trailing constraints with constant 0 of each. So, it will always keep same size with respect to parent view that you have added in IB . If you want rational(like half height and width of parent view or anything else) height or width then you can manage it by playing with constant and multiplier .

If you don't have idea that how to add constraints programmatically then you can refer This SO post .

Answer 2

Here comes viewDidLayoutSubviews to resolve our issue,

Description:

When the bounds change for a view controller's view, the view adjusts the positions of its subviews and then the system calls this method.

Instead of viewDidLoad use viewDidLayoutSubviews as follows

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    let imageTemplateView: ImageTemplateView = ImageTemplateView(frame: frame)
    cardView.addSubview(imageTemplateView)
    imageTemplateView.clipsToBounds = true
}

UPDATE:

• Declare variable above viewdidload

   var imageTemplateView: ImageTemplateView = ImageTemplateView() 

• set frame and add it as sub view in viewdidload

   override func viewDidLoad() { imageTemplateView = ImageTemplateView(frame: frame) cardView.addSubview(imageTemplateView) imageTemplateView.clipsToBounds = true } 

• In viewDidLayoutSubviews just set the frame alone,so that whenever orientation changes ImageTemplateView 's frame will be updated

   override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() imageTemplateView = ImageTemplateView(frame: frame) } 

Answer 3

try this

@IBOutlet weak var cardView: UIView!
var imageTemplateView:ImageTemplateView!

override func viewDidLoad() 
{
    super.viewDidLoad()
    imageTemplateView = ImageTemplateView(frame: cardView.bounds)
    cardView.addSubview(imageTemplateView)
}

override func viewDidLayoutSubviews() 
{
    super.viewDidLayoutSubviews()
    imageTemplateView.frame = cardView.bounds
}

Answer 4

You can use Size Class feature. Set constraint and add view base or orientation change. Check this Tutorial http://www.hossamghareeb.com/size-classes-tutorial/