在保存的照片顶部打印图像(swift3)

func addImageToPhoto(photo: UIImage, image: UIImage) -> UIImage? {
    let size = photo.size
    
    // 创建一个基于位图的上下文
    UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
    
    // 将照片绘制到上下文中
    photo.draw(in: CGRect(origin: CGPoint.zero, size: size))
    
    // 计算图像的位置和大小
    let imageWidth: CGFloat = size.width / 2.0
    let imageHeight: CGFloat = size.height / 4.0
    let imageX: CGFloat = (size.width - imageWidth) / 2.0
    let imageY: CGFloat = size.height / 8.0
    
    // 将图像绘制到上下文中
    image.draw(in: CGRect(x: imageX, y: imageY, width: imageWidth, height: imageHeight))
    
    // 从上下文中获取合成后的图像
    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    
    // 结束上下文
    UIGraphicsEndImageContext()
    
    return newImage
}

let photo = UIImage(named: "photo.jpg")
let image = UIImage(named: "logo.png")
let newPhoto = addImageToPhoto(photo: photo, image: image)