What should the zoom scale be in UIScrollView?

What should the zoom scale be in UIScrollView?

A zoom scale of less than 1 shows a zoomed-out version of the content, and a zoom scale greater than 1 shows the content zoomed in. To get the minimum zoom scale, you first calculate the required zoom to fit the image view snugly within the scroll view, based on its width. You then calculate the same for the height.

How is zoomedphotoviewcontroller conforms to uiscrollviewdelegate?

This makes ZoomedPhotoViewController conform to UIScrollViewDelegate and implements viewForZooming (in:). The scroll view calls this method to determine which of its subviews to scale when the user pinches the image. Here, you tell it to scale imageView. This method calculates the zoom scale for the scroll view.

How do I set UIScrollView to autoresizingmask?

Since setting this position is so common when working with scroll views, UIScrollView has a contentOffset property that you can change which will have the same effect as changing the bounds origin. Paste the following statement after the line that sets the scroll view’s autoresizingMask.

How does updateconstraintsforsize get around UIScrollView?

updateConstraintsForSize (_:) gets around an annoyance with UIScrollView: If the scroll view’s content size is smaller than its bounds, it places the contents at the top-left of the screen, rather than the center. You center the image vertically by subtracting the height of imageView from the view ‘s height and dividing the result in half.

How to set up a scroll view in storyboard?

To kick off this UIScrollView tutorial, you’ll set up a scroll view that lets the user pan and zoom an image. Open Main.storyboard and drag a Scroll view from the Object Library onto the document outline, right below View on the Zoomed Photo View Controller scene. Then, move Image View inside your newly-added Scroll View.