Auto Layout constraint on CALayer IOS

Question

Hi I am developing iPhone application in which I tried to set one side border for edittext. I did this in following way:

 int borderWidth = 1; CALayer *leftBorder = [CALayer layer];  leftBorder.borderColor = [UIColor whiteColor].CGColor; leftBorder.borderWidth = borderWidth;  leftBorder.frame = CGRectMake(0, textField.frame.size.height - borderWidth, textField                               .frame.size.width, borderWidth); [textField.layer addSublayer:leftBorder]; 

I put some constraints on my edittext in IB so that when I rotate my device it will adjust width of text field according to that. My problem is that adjusts the width of edittext not adjusting the width of CALayer which I set for my edit text. So I think I have to put some constraints for my CALayer item as well. But I dont know how to do that. ANy one knows about this? Need Help. Thank you.

Answer 1

the whole autoresizing business is view-specific. layers don't autoresize.

what you have to do -- in code -- is to resize the layer yourself

e.g.

in a viewController you would do

- (void) viewDidLayoutSubviews {   [super viewDidLayoutSubviews]; //if you want superclass's behaviour...    // resize your layers based on the view's new frame   self.editViewBorderLayer.frame = self.editView.bounds; } 

or in a custom UIView you could use

- (void)layoutSubviews {   [super layoutSubviews]; //if you want superclass's behaviour...  (and lay outing of children)   // resize your layers based on the view's new frame   layer.frame = self.bounds; } 

Answer 2

In Swift 5, you can try the following solution:

Use KVO, for the path "YourView.bounds" as given below.

self.addObserver(self, forKeyPath: "YourView.bounds", options: .new, context: nil) 

Then handle it as given below.

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {         if keyPath == "YourView.bounds" {             YourLayer.frame = YourView.bounds             return         }         super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)     } 

More info about this here