Take screenshot of visible area of UIScrollView

Question

I have a UIScrollView as subview of a view controller main view. I'm trying to save a screenshot of whatever is visible in the frame of the UIScrollView only.

UIGraphicsBeginImageContextWithOptions(imageScrollView.bounds.size, false, UIScreen.main.scale) let context = UIGraphicsGetCurrentContext() context?.translateBy(x: 0, y: 0)

    view.layer.render(in: context!)
    let visibleScrollViewImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()


    let popupImageView = UIImageView(image: visibleScrollViewImage)
    popupImageView.layer.borderColor = UIColor.white.cgColor
    popupImageView.layer.borderWidth = 4
    popupImageView.frame = CGRect(origin: CGPoint(x: 0, y: 400), size: CGSize(width: 400, height: 400))

    imageScrollView.removeFromSuperview()

    view.addSubview(popupImageView)

The part with the popupImageView is just to test out and see what is actually saving, it seems there is some offset problem, the horizontal axis is fine but i seem to be getting just the top third of the image I want, and above that is just dark space.

Seems like it must be a pretty easy solution but I've searched through all similar questions and can't find an answers.

Thanks heaps!

Check this answer: To get the screenshot, use this: https://stackoverflow.com/a/53956500/10842413 — iOS Developer, Mar 05 '19 at 10:16
I don’t think you got the question, I need the screenshot from the uiscrollview. — Tin Luong, Mar 05 '19 at 10:22

score 1 · Accepted Answer · answered Mar 05 '19 at 11:44

Try the following. If I do it with a UITableView control, it works.

import UIKit

class ViewController: UIViewController {
    @IBAction func snapTapped(_ sender: UIButton) {
        UIGraphicsBeginImageContextWithOptions(imageScrollView.bounds.size, true, 1.0)
        imageScrollView.drawHierarchy(in: CGRect(origin: CGPoint.zero, size: imageScrollView.bounds.size), afterScreenUpdates: true)
        if let image = UIGraphicsGetImageFromCurrentImageContext() {
            UIGraphicsEndImageContext()
            myImageView.image = image
        }
    }
}

Yes, my hero you’ve saved me! Thanks so much – Tin Luong Mar 05 '19 at 12:20 — Tin Luong, Mar 05 '19 at 12:20

iOS Developer · Answer 2 · 2019-03-05T10:35:57.013

0

func screenShotMethod()->UIImage
{
  let layer = self.imageScrollView.layer
  let scale = UIScreen.main.scale
  UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale);

  layer.render(in: UIGraphicsGetCurrentContext()!)
  let screenshot = UIGraphicsGetImageFromCurrentImageContext()
  UIGraphicsEndImageContext()

  return screenshot!
}

edited Mar 05 '19 at 10:35

answered Mar 05 '19 at 10:27

iOS Developer

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When I do that now I get a completely blank image. – Tin Luong Mar 05 '19 at 11:09
Are you calling this function on button click or on screen loading? – iOS Developer Mar 05 '19 at 11:26
On button click, the uiscrollview has an image view that I zoom and move about inside the scroll view, then I click save button to save exactly what’s visible in the scroll view – Tin Luong Mar 05 '19 at 11:30
Can you share some code to check the problem? Or first try to add the scrollview in a view and take the screenshot of that view – iOS Developer Mar 05 '19 at 11:38

Take screenshot of visible area of UIScrollView

2 Answers2