Turn off Zooming in UIScrollView

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.