ScrollView doesn't scroll in swift

Question

I have an UIView and add an UIScrollView to it. Inside the scrollView is an UIImageView.
I want to zoom the image view by pressing a button. If the image view is zoomed you should be able to scroll but that's not working.

Currently I have that:

self.imageView = UIImageView()
self.imageView.image = image
self.imageView.frame = self.contentView.bounds

self.scrollView = UIScrollView()
self.scrollView.frame = self.contentView.bounds
self.scrollView.contentSize = self.contentView.bounds.size
self.scrollView.addSubview(self.imageView)

self.contentView.addSubview(self.scrollView)

and that:

@IBAction func zoomPicture() {
    if (scale <= 1.5) {
        scale = scale + 0.1
        scrollView.transform = CGAffineTransformMakeScale(scale, scale)
        scrollView.zoomScale = scale
        scrollView.maximumZoomScale = 1.5
        scrollView.minimumZoomScale = 1.0
        scrollView.contentSize = contentView.bounds.size
        scrollView.scrollEnabled = true
    }
}

my class also implements UIScrollViewDelegateand I set the delegate in the viewDidLoad() function. I have also added the viewForZoomingInScrollView function. The zoom works but I can't scroll.

Try to set `self.scrollView.contentSize` bigger than `self.contentView.bounds` — Ashish Thakkar, Aug 09 '16 at 06:08
Nice, works! Does it matter how much the content size is bigger or not? — mafioso, Aug 09 '16 at 06:17
I think you answer in this link, http://stackoverflow.com/questions/11318845/ios-add-imageview-in-a-scrollview-to-have-zoom — Keyur Hirani, Aug 09 '16 at 06:17
@mafioso yes it matters and always try to set content size bigger, why this happens, is in answer i posted below. — Ashish Thakkar, Aug 09 '16 at 06:22

Ashish Thakkar · Accepted Answer · 2016-08-09T06:28:00.213

8

For this issue you have to set self.scrollView.contentSize bigger than self.contentView.bounds so it get proper space to scroll.

replace this line

self.scrollView.contentSize = self.contentView.bounds.size

to this:

self.scrollView.contentSize = self.contentView.bounds.size*2 //or what ever size you want to set

edited Aug 09 '16 at 06:28

answered Aug 09 '16 at 06:20

Ashish Thakkar

944
8
27

1

do you also know why horizontal scrolling in landscape mode doesn't work? – mafioso Aug 09 '16 at 06:35
have you enabled horizontal scroll from property ? – Ashish Thakkar Aug 09 '16 at 06:39
umm no I don't think so how would I do that? – mafioso Aug 09 '16 at 06:41
you will get detailed about scroll view here https://www.appcoda.com/uiscrollview-introduction/ check this it will helpful – Ashish Thakkar Aug 09 '16 at 07:08

score 0 · Answer 2 · answered Aug 09 '16 at 06:17

Try this:

@IBAction func zoomPicture() {
    if (scale <= 1.5) {
        scale = scale + 0.1
        scrollView.zoomScale = scale
        scrollView.maximumZoomScale = 1.5
        scrollView.minimumZoomScale = 1.0
        let size = contentView.bounds.size
        scrollView.contentSize = CGSize(width: size.width * scale, height: size.height * scale)
        scrollView.scrollEnabled = true
    }
}

ScrollView doesn't scroll in swift

2 Answers2