Turn off Zooming in UIScrollView - ios

Question

Does anyone know a way to temporarily turn off zooming when using a UIScrollView?
I see that you can disable scrolling using the following:
self.scrollView.scrollEnabled = false;
but I'm not seeing a similar command for zooming. Any thoughts?

Answer 1

If you want to disable the user's ability to zoom through gestures then in iOS 5 and above you can disable the pinch gesture. This still allows you to control the scroll view from code...
scrollView.pinchGestureRecognizer.enabled = NO;
similarly for pan...
scrollView.panGestureRecognizer.enabled = NO;
This must be called in - (void)viewDidAppear:(BOOL)animated or later as otherwise the system resets it to enabled.
Swift 4.x and above:
imageZoomView.pinchGestureRecognizer?.isEnabled = false / true

Answer 2

Following fbrereto's advice above, I created two functions lockZoom and unlockZoom. When locking Zoom i copied my max and min zoom scales to variables then set the max and min zoom scale to 1.0. Unlocking zoom just reverses the process.
-(void)lockZoom
{
maximumZoomScale = self.scrollView.maximumZoomScale;
minimumZoomScale = self.scrollView.minimumZoomScale;
self.scrollView.maximumZoomScale = 1.0;
self.scrollView.minimumZoomScale = 1.0;
}
-(void)unlockZoom
{
self.scrollView.maximumZoomScale = maximumZoomScale;
self.scrollView.minimumZoomScale = minimumZoomScale;
}

Answer 3

Also you can return "nil" as zooming view in UIScrollViewDelegate:
- (UIView *) viewForZoomingInScrollView:(UIScrollView *) scrollView
{
return canZoom?view:nil;
}

Answer 4

Check setting minimumZoomScale and maximumZoomScale; According to the docs:
maximumZoomScale must be greater than minimumZoomScale for zooming to be enabled.
So, setting the values to be the same should disable zooming.

Answer 5

I have tried setting minimumZoomScale and maximumZoomScale properties of UIScrollView to 1 or isMultipleTouchEnabled property of UIView to false or return nil from viewForZooming(in:) of UIScrollViewDelegate but none worked. In my case, after several trial and error, the following works in my case [Tested on iOS 10.3]:
class MyViewController: UIViewController {
var webView: WKWebView?
override viewDidLoad() {
super.viewDidLoad()
//...
self.webView.scrollView.delegate = self
//...
}
}
extension MyViewController: UIScrollViewDelegate {
func scrollViewWillBeginZooming(_ scrollView: UIScrollView, with view: UIView?) {
scrollView.pinchGestureRecognizer?.isEnabled = false
}
}

Answer 6

I know this is a really old question but I made a slight variation for my purposes.
I wanted to be able to easily tell if the zooming was in fact enabled/disabled without relying on a comparison between scrollView.minimumZoomScale == scrollView.maximumZoomScale, which could possibly not reflect whether zooming was actually enabled/disabled.
So I did this
// .h
#property (assign, nonatomic, getter=isZoomEnabled) BOOL zoomEnabled;
// .m
#synthesize zoomEnabled = _zoomEnabled;
- (void)setZoomEnabled:(BOOL)zoomEnabled;
{
_zoomEnabled = zoomEnabled;
UIScrollView *scrollView = self.scrollView;
if (zoomEnabled) {
scrollView.minimumZoomScale = self.minimumZoomScale;
scrollView.maximumZoomScale = self.maximumZoomScale;
} else {
scrollView.minimumZoomScale = 0.0f;
scrollView.maximumZoomScale = 0.0f;
}
}
The values for self.minimumZoomScale and self.maximumZoomScale are set at the time the UIScrollView is configured.
This gives me the ability to set/ask if zooming is enabled.
myViewController.zoomEnabled = YES;
myViewController.isZoomEnabled;

Answer 7

here, my solution for stop zooming on scrollview.
self.scrollView.minimumZoomScale=self.scrollView.maximumZoomScale;

Answer 8

Swift 3 Version:
func lockScrollViewZooming() {
scrollView.minimumZoomScale = 1.0
scrollView.maximumZoomScale = 1.0
scrollView.bounces = false
scrollView.bouncesZoom = false
// Also, if you have double tap recognizer,
// remember to remove it
scrollView.removeGestureRecognizer(doubleTapGestureRecognizer)
}
func unlockScrollViewZooming() {
scrollView.minimumZoomScale = 1.0
scrollView.maximumZoomScale = 4.0
scrollView.bounces = true
scrollView.bouncesZoom = true
// Also, if you have double tap recognizer,
// remember to add it
scrollView.removeGestureRecognizer(doubleTapGestureRecognizer)
}
Note that doubleTapGestureRecognizer should be an instance variable. It should be similar to:
private lazy var doubleTapGestureRecognizer: UITapGestureRecognizer = {
let doubleTapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap(_:)))
doubleTapGestureRecognizer.numberOfTapsRequired = 2
doubleTapGestureRecognizer.delegate = self
return doubleTapGestureRecognizer
}()
#objc private func handleDoubleTap(_ recognizer: UITapGestureRecognizer) {
//scrollView.setZoomScale((scrollView.zoomScale > scrollView.minimumZoomScale) ? scrollView.minimumZoomScale : scrollView.maximumZoomScale, animated: true)
if scrollView.zoomScale > scrollView.minimumZoomScale {
scrollView.setZoomScale(scrollView.minimumZoomScale, animated: true)
} else {
let touchLocation = recognizer.location(in: recognizer.view)
scrollView.zoom(to: CGRect(origin: touchLocation, size: CGSize(width: 22.0, height: 20.0)), animated: true)
}
}

Answer 9

You need to turn off Two Fingers and Double Tap of scroll view
self.scrollView.delegate = self
And
extension YourViewController: UIScrollViewDelegate {
func scrollViewWillBeginZooming(_ scrollView: UIScrollView, with view: UIView?) {
scrollView.pinchGestureRecognizer?.isEnabled = false
}
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return nil
}
}

Answer 10

If you want to disable only zooming with pinch gesture, below code does the trick.
scrollView.pinchGestureRecognizer?.requireGestureRecognizerToFail(scrollView.panGestureRecognizer)