How to change the height and width of a button in iOS app using Swift 4.0 which is developed using Swift 3.0

Question

I am completely new to iOS development and I am supposed to fix some bugs in an iOS app which is made using Swift 3.0 and Xcode 8 and it works almost fine. But when I open it with Xcode 9 and Swift 4.0 it shows some buttons way different that they were before.

Here is the source code for one of those buttons.

let button: UIButton = UIButton.init(type: UIButtonType.custom)
    //set image for button
    button.setImage(UIImage(named: "menu.png"), for: UIControlState())
    button.frame = CGRect(x: 0, y: 0, width: 30, height: 23)
    let barButton = UIBarButtonItem(customView: button)
    button.addTarget(self, action: #selector(ViewController.shareButtonPressed), for: UIControlEvents.touchUpInside)

    self.navigationItem.leftBarButtonItem = barButton

this code is inside the ViewDidLoad method. My problem is when I remove,

button.setImage(UIImage(named: "menu.png"), for: UIControlState())

it disappears the button but when I change the height and the width from,

button.frame = CGRect(x: 0, y: 0, width: 30, height: 23)

it changes nothing. My problem is how can I fix this bug. Any suggestion, answer is highly appreciated and if the given details are not enough, please mention. Thank you!

Answer 1

Beginning with iOS 11, views added to toolbars using UIBarButtonItem using UIBarButtonItem(customView:) are now laid out using auto layout. You should add sizing constraints on your button. For example:

button.widthAnchor.constraintEqualToConstant(30.0).isActive = true
button.heightAnchor.constraintEqualToConstant(23.0).isActive = true

Otherwise, auto layout will use the intrinsic content size of your header view which is likely not what you expect.

For more information see the WWDC 2017 session Updating your app for iOS 11.

Answer 2

swift 4:

button.widthAnchor.constraint(equalToConstant: 30.0).isActive = true
button.heightAnchor.constraint(equalToConstant: 20.0).isActive = true