Image Zoom using uiscrollview working unexpectedly. swift - ios

Question

I was developing an app in which a user adds a photo and edits it. When the image is added to imageView and zoomed it works fine but when I add a new image, unexpectedly the scrollView increases in length and the image is viewed in the middle of the scrollView has coded, but the scrollView increases in size. I have to scroll to the middle to view the image. Below is the code I am using.
#IBAction func addPhotoTrigered(_ sender: Any) {
addPhotoCall()
}
func addPhotoCall() {
print("dsds")
let image = UIImagePickerController()
image.delegate = self
image.sourceType = UIImagePickerControllerSourceType.photoLibrary
image.allowsEditing = false
self.present(image, animated: true) {
}
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
imagePic = info[UIImagePickerControllerOriginalImage] as? UIImage
addImageView.isHidden = true
imageView.image = imagePic
newImageButton.isHidden = false
photoStatus = true
imageView.contentMode = UIViewContentMode.center
imageView.frame = CGRect(origin: CGPoint(x: 0, y: 0), size: CGSize(width: imagePic!.size.width, height: imagePic!.size.height))
print(imageView.frame)
scrollView.contentSize = imagePic!.size
let scrollViewFrame = scrollView.frame
let scrollWidth = scrollViewFrame.size.width / scrollView.contentSize.width
let scrollHeight = scrollViewFrame.size.height / scrollView.contentSize.height
let minScale = min(scrollHeight, scrollWidth)
scrollView.minimumZoomScale = minScale
scrollView.maximumZoomScale = 1.0
scrollView.zoomScale = minScale
centreScrollViewContent()
self.dismiss(animated: true, completion: nil)
}
func centreScrollViewContent() {
let boundSize = scrollView.bounds.size
var contentFrame = imageView.frame
if contentFrame.size.width < boundSize.width {
contentFrame.origin.x = (boundSize.width - contentFrame.size.width) / 2
} else {
contentFrame.origin.x = 0
}
if contentFrame.size.height < boundSize.height {
contentFrame.origin.y = (boundSize.height - contentFrame.size.height) / 2
} else {
contentFrame.origin.y = 0
}
imageView.frame = contentFrame
}
func scrollViewDidZoom(_ scrollView: UIScrollView) {
centreScrollViewContent()
}
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return imageView
}
#IBAction func newImageTrigered(_ sender: Any) {
imageView.image = nil
addImageView.isHidden = false
newImageButton.isHidden = true
}
please fix the code. I have tried many ways but was not able to understand why its happening.

Answer 1

make an outlet from your scroll view and put delegate self and add uiscrollViewDelegate to viewcontroller and then it should work
i have a sample code to
class ViewController: UIViewController, UIScrollViewDelegate {
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var imageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
scrollView.delegate = self
updateZoomFor(size: scrollView.bounds.size)
}
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return imageView
}
func updateZoomFor(size: CGSize) {
let widthScale = size.width / imageView.bounds.width
let heightScale = size.height / imageView.bounds.height
let scale = min(widthScale, heightScale)
scrollView.minimumZoomScale = scale
scrollView.maximumZoomScale = 5
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}