[iOS]コードでスナップショットを撮る

ios-snapshot.md

// UIScrollView全体のスナップショット
// https://gist.github.com/thestoics/1204051
extension UIScrollView {
     public var snapshot: UIImage? {
         UIGraphicsBeginImageContextWithOptions(contentSize, false, 0)
         defer {
             UIGraphicsEndImageContext()
         }
         guard let context = UIGraphicsGetCurrentContext() else { return nil }
         let previousFrame = frame
         frame = CGRect(origin: frame.origin, size: contentSize)
         layer.render(in: context)
         frame = previousFrame
         return UIGraphicsGetImageFromCurrentImageContext()
     }
 }

// navigationBarのスクリーンショット
let rect = self.navigationController!.navigationBar.frame
UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
defer {
     UIGraphicsEndImageContext()
}
guard let context: CGContext = UIGraphicsGetCurrentContext() else { return nil }
self.navigationController!.navigationBar.layer.render(in: context)
let capturedImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()

return capturedImage