iOS 截屏, 获得普通view和ScrollView的UIImage （Swift 4）

/****************************截屏**************************************/
//MARK: 截屏
///截屏 View
func screenImageWithView(cutView: UIView)-> UIImage {
    //截屏区域；是否透明；清晰度
    var image = UIImage()
    UIGraphicsBeginImageContextWithOptions(cutView.frame.size, true, UIScreen.main.scale)
    cutView.layer.render(in: UIGraphicsGetCurrentContext()!)
    image = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsGetCurrentContext()
    return image
}

//MARK: 截屏scrollview
/// 截屏scrollview
func cutFullImageWithView(scrollView:UIScrollView) -> UIImage {
    // 记录当前的scrollView的偏移量和坐标
    let currentContentOffSet:CGPoint = scrollView.contentOffset
    let currentFrame:CGRect = scrollView.frame;
    
    // 设置为zero和相应的坐标
    scrollView.contentOffset = CGPoint.zero
    scrollView.frame = CGRect.init(x: 0, y: 0, width: scrollView.frame.size.width, height: scrollView.frame.size.height)
    
    // 参数①：截屏区域  参数②：是否透明  参数③：清晰度
    UIGraphicsBeginImageContextWithOptions(scrollView.contentSize, true, UIScreen.main.scale)
    scrollView.layer.render(in: UIGraphicsGetCurrentContext()!)
    let image:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    
    // 重新设置原来的参数
    scrollView.contentOffset = currentContentOffSet
    scrollView.frame = currentFrame
    
    UIGraphicsEndImageContext()
    
    return image
}