How to get the frame of a view inside another view

问题:

I have an UIImageView in the self.view (the main View) and inside it there is a UIButton. I want to know what's the frame of UIButton in self.view not in UIImageView.

回答1:

I guess you are looking for this method

– convertRect:toView:

// Swift
let frame = imageView.convert(button.frame, to: self.view)

// Objective-C
CGRect frame = [imageView convertRect:button.frame toView:self.view];

回答2:

There are four UIView methods which can help you, converting CGPoints and CGRects from one UIView coordinate reference to another:

– convertPoint:toView:
– convertPoint:fromView:
– convertRect:toView:
– convertRect:fromView:

so you can try

CGRect f = [imageView convertRect:button.frame toView:self.view];

or

CGRect f = [self.view convertRect:button.frame fromView:imageView];

回答3:

Swift 3

You can convert the button's frame to the view's coordinate system with this:

self.view.convert(myButton.frame, from: myButton.superview)

---

Make sure to put your logic inside viewDidLayoutSubviews and not viewDidLoad. Geometry related operations should be performed after subviews are laid out, otherwise they may not work properly.

class ViewController: UIViewController {

    @IBOutlet weak var myImageView: UIImageView!
    @IBOutlet weak var myButton: UIButton!

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        let buttonFrame = self.view.convert(myButton.frame, from: myButton.superview)
    }
}

You can just reference myButton.superview instead of myImageView when converting the frame.

---

Here are more options for converting a CGPoint or CGRect.

self.view.convert(point: CGPoint, from: UICoordinateSpace)
self.view.convert(point: CGPoint, from: UIView)             
self.view.convert(rect: CGRect, from: UICoordinateSpace)
self.view.convert(rect: CGRect, from: UIView)

self.view.convert(point: CGPoint, to: UICoordinateSpace)
self.view.convert(point: CGPoint, to: UIView)
self.view.convert(rect: CGRect, to: UICoordinateSpace)
self.view.convert(rect: CGRect, to: UIView)

---

See the Apple Developer Docs for more on converting a CGPoint or CGRect.

回答4:

Something like this? might be totally wrong, dint really thinkt it through ;p

CGRect frame = CGRectMake((self.view.frame.origin.x-imageview.frame.origin.x) +btn.frame.origin.x,
                          (self.view.frame.origin.y.imageview.frame.origin.y)+btn.frame.origin.y,
                          btn.frame.size.width,
                          btn.frame.size.height);

I don't know if theres any easier way.