UIBarButtonItem: How can I find its frame?

Question

I have a button in a toolbar. How can I grab its frame? Do UIBarButtonItems not have a frame property?

Answer 1

Try this one;

UIBarButtonItem *item = ... ;
UIView *view = [item valueForKey:@"view"];
CGFloat width;
if(view){
    width=[view frame].size.width;
}
else{
    width=(CGFloat)0.0 ;
}

Answer 2

This way works best for me:

UIView *targetView = (UIView *)[yourBarButton performSelector:@selector(view)];
CGRect rect = targetView.frame;

Answer 3

Oof, lots of rough answers in this thread. Here's the right way to do it:

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))
    }
}

Answer 4

With Swift, if you needs to often work with bar button items, you should implement an extension like this:

extension UIBarButtonItem {

    var frame: CGRect? {
        guard let view = self.value(forKey: "view") as? UIView else {
            return nil
        }
        return view.frame
    }

}

Then in your code you can access easily:

if let frame = self.navigationItem.rightBarButtonItems?.first?.frame {
    // do whatever with frame            
}

Answer 5

Thanks to Anoop Vaidya for the suggested answer. An alternative could be (providing you know the position of the button in the toolbar)

UIView *view= (UIView *)[self.toolbar.subviews objectAtIndex:0]; // 0 for the first item


CGRect viewframe = view.frame;

Answer 6

Here's what I'm using in iOS 11 & Swift 4. It could be a little cleaner without the optional but I'm playing it safe:

extension UIBarButtonItem {
    var view: UIView? {
        return perform(#selector(getter: UIViewController.view)).takeRetainedValue() as? UIView
    }
}

And usage:

if let barButtonFrame = myBarButtonItem.view?.frame {
    // etc...
}

Edit: I don't recommend using this anymore. I ended up changing my implementation to use UIBarButtonItems with custom views, like Dan's answer

Answer 7

-(CGRect) getBarItemRc :(UIBarButtonItem *)item{
    UIView *view = [item valueForKey:@"view"];
    return [view frame];
}

Answer 8

You can create a UIBarButtonItem with a custom view, which is a UIButton, then you can do whatever you want. :]

Answer 9

in Swift 4.2 and inspired with luca

extension UIBarButtonItem {

    var frame:CGRect?{
        return (value(forKey: "view") as? UIView)?.frame
    }

}


guard let frame = self.navigationItem.rightBarButtonItems?.first?.frame else{ return }

Answer 10

You can roughly calculate it by using properties like layoutMargins and frame on the navigationBar, combined with icon size guides from Human Interface Guidelines and take into count the current device orientation:

- (CGRect)rightBarButtonFrame {
    CGFloat imageWidth = 28.0;
    CGFloat imageHeight = UIDevice.currentDevice.orientation == UIDeviceOrientationLandscapeLeft || UIDevice.currentDevice.orientation == UIDeviceOrientationLandscapeRight ? 18.0 : 28.0;
    UIEdgeInsets navigationBarLayoutMargins = self.navigationController.navigationBar.layoutMargins;
    CGRect navigationBarFrame = self.navigationController.navigationBar.frame;
    return CGRectMake(navigationBarFrame.size.width-(navigationBarLayoutMargins.right + imageWidth), navigationBarFrame.origin.y + navigationBarLayoutMargins.top, imageWidth, imageHeight);
}

Answer 11

Try this implementation:

@implementation UIBarButtonItem(Extras)

- (CGRect)frameInView:(UIView *)v {

    UIView *theView = self.customView;
    if (!theView.superview && [self respondsToSelector:@selector(view)]) {
        theView = [self performSelector:@selector(view)];
    }

    UIView *parentView = theView.superview;
    NSArray *subviews = parentView.subviews;

    NSUInteger indexOfView = [subviews indexOfObject:theView];
    NSUInteger subviewCount = subviews.count;

    if (subviewCount > 0 && indexOfView != NSNotFound) {
        UIView *button = [parentView.subviews objectAtIndex:indexOfView];
        return [button convertRect:button.bounds toView:v];
    } else {
        return CGRectZero;
    }
}

@end

Answer 12

You should do a loop over the subviews and check their type or their contents for identifying. It is not safe to access view by kvo and you cannot be sure about the index.

Answer 13

Check out this answer: How to apply borders and corner radius to UIBarButtonItem? which explains how to loop over subviews to find the frame of a button.

Answer 14

I used a view on the bar button item with a tag on the view:

for view in bottomToolbar.subviews {
   if let stackView = view.subviews.filter({$0 is UIStackView}).first {
       //target view has tag = 88
       if let targetView = stackView.subviews.filter({$0.viewWithTag(88) != nil}).first {                                
          //do something with target view
   }
}

}

Answer 15

Swift 4 up The current best way to do it is to access its frame from :

self.navigationItem.rightBarButtonItems by

let customView = navigationItem.rightBarButtonItems?.first?.customView // access the first added customView

Accessing this way is safer than accessing private api.

• check out the answer in this :

After Add a CustomView to navigationItem, CustomView always return nil