This will allow you to take a screenshot of a UIView, but more importantly only a section of that view

Screenshot.swift

//
//  Screenshot.swift
//
// 1) Take a picture of a UIView
// 2) Take a picture of a UIView's subframe. EG. Fullscreen UIView with a
//     small square box in the middle, it will only save what's visible in the box frame
//     but not the box itself

import Foundation
import UIKit

extension UIView {
    
    class func image(view: UIView, subview: UIView? = nil) -> UIImage? {
        
        UIGraphicsBeginImageContextWithOptions(view.frame.size, false, 0)
    
        view.drawHierarchy(in: view.frame, afterScreenUpdates: true)
        
        var image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!

        UIGraphicsEndImageContext()
        
        if(subview != nil){
            var rect = (subview?.frame)!
            rect.size.height *= image.scale  //MOST IMPORTANT
            rect.size.width *= image.scale    //TOOK ME DAYS TO FIGURE THIS OUT
            let imageRef = image.cgImage!.cropping(to: rect)
            image = UIImage(cgImage: imageRef!, scale: image.scale, orientation: image.imageOrientation)
        }
        
        return image
    }
    
    func image() -> UIImage? {
        return UIView.image(view: self)
    }
    
    func image(withSubview: UIView) -> UIImage? {
        return UIView.image(view: self, subview: withSubview)
    }
}

does this save to camera roll?

also, how would i call this with a button?

is capture my screen during video recording ?

You can do this simpler by shifting the UIView. Think of a printed photo, and a matchbox. The Matchbox should cover the section you want, and its anchored to the top left of the image. To get it into the middle somewhere, you move the paper to the left and up, leaving the matchbox where it is. In code, to do this, you create a CGRect with negative x and y coordinates, but use the view's size alone.

I took this code and did the above modifications to it: https://gist.github.com/dhoerl/ea583ed8e9e94a6a44e276dc2ba55390

THANK YOU NITRAG!

One correction for taking image over subview is to adjust the origin point too:
rect.origin.x = subview.frame.origin.x * image.scale rect.origin.y = subview.frame.origin.y * image.scale