ＩＯＳ Swift 擷取當前螢幕產生縮圖

         func screenshot() -> UIImage {

            var imageSize = CGSize.zero

    

            let orientation = UIApplication.shared.statusBarOrientation

            if UIInterfaceOrientationIsPortrait(orientation) {

                imageSize = UIScreen.main.bounds.size

            } else {

                imageSize = CGSize(width: UIScreen.main.bounds.size.height, height: UIScreen.main.bounds.size.width)

            }

    

            UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)

            for window in UIApplication.shared.windows {

                window.drawHierarchy(in: window.bounds, afterScreenUpdates: true)

            }

    

            let image = UIGraphicsGetImageFromCurrentImageContext()

            UIGraphicsEndImageContext()

            return image!

        }