Get the frame of UIBarButtonItem in Swift?

Question

how could I get the frame of a rightbarbuttonItem in swift? I found this : UIBarButtonItem: How can I find its frame? but it says cannot convert NSString to UIView, or cannot convert NSString to String :

let str : NSString = "view" //or type String
let theView : UIView = self.navigationItem.rightBarButtonItem!.valueForKey("view")//or 'str'

The goal is to remove the rightBarButtonItem, add an imageView instead, and move it with a fadeOut effect.

Thanks

score 39 · Accepted Answer · edited Sep 05 '17 at 13:35

39

You should try it like:

var barButtonItem = self.navigationItem.rightBarButtonItem!
var buttonItemView = barButtonItem.valueForKey("view")

var buttonItemSize = buttonItemView?.size

Edit (Swift 3):

var barButtonItem = self.navigationItem.rightBarButtonItem!
let buttonItemView = barButtonItem.value(forKey: "view") as? UIView
var buttonItemSize = buttonItemView?.size

edited Sep 05 '17 at 13:35

jarora

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answered Mar 11 '15 at 15:47

Christian

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perfect thanks, with a `AnyObject?` to buttonItemView it works fine – Paul Mar 11 '15 at 16:21
2

doesn't work with the new SDK and Xcode 8.3.1 Do you have an alternative? – JVS Apr 27 '17 at 12:52
@JVS `.valueForKey` returns an Any?. Cast to UIView to make it compile. `var buttonItemSize = (buttonItemView as? UIView).size` – LOP_Luke Apr 28 '17 at 15:10
swift3 like that: let buttonItemSize = (buttonItemView as! UIView).frame.size – iHTCboy May 21 '17 at 04:44
9

This seems to be broken in Xcode 9 beta 6 targeting iOS 11... Is anyone else seeing the same? – Chase Holland Aug 23 '17 at 22:27
This works well in Xcode 10.2.1. It's just called `value(forKey:)` now in Swift 4 – marsbear Jul 15 '19 at 14:28

score 5 · Answer 2 · answered Sep 28 '17 at 09:02

5

In Swift4, XCode9

    for view in (self.navigationController?.navigationBar.subviews)! {
        if let findClass = NSClassFromString("_UINavigationBarContentView") {
            if view.isKind(of: findClass) {
                if let barView = self.navigationItem.rightBarButtonItem?.value(forKey: "view") as? UIView {
                    let barFrame = barView.frame
                    let rect = barView.convert(barFrame, to: view)
                }
            }
        }
    }

answered Sep 28 '17 at 09:02

ePing Tu

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@Aerox try to call this in viewDidAppear() method – Hosny Nov 20 '17 at 12:06
@Aerox you can also try calling this in `viewDidLayoutSubviews`, but you should be careful to avoid calling it more that it needs to be called. – ThomasW Jan 11 '18 at 03:19

Dan Stenmark · Answer 3 · 2017-11-26T01:41:55.733

import UIKit

class ViewController: UIViewController {

    let customButton = UIButton(type: .system)

    override func viewDidLoad() {
        super.viewDidLoad()

        customButton.setImage(UIImage(named: "myImage"), for: .normal)
        self.navigationItem.rightBarButtonItem = UIBarButtonItem(customView: customButton)
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        print(self.customButton.convert(self.customButton.frame, to: nil))
    }
}

You must use UIBarButtonItem objects created with customView for this; UIBarButtonItem objects created the regular way don't have enough information exposed. It's important that the frame be looked up after the parent UINavigationController's UINavigationBar has completely laid out its entire subview tree. For most use cases, the visible UIViewController's viewDidAppear is a good enough approximation of this.

Get the frame of UIBarButtonItem in Swift?

3 Answers3

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