Swift计算UIImage尺寸CGSize

import ImageIO

extension UIImage {

    /**

    *  根据图片url获取网络图片尺寸

    */

    class func getSizeWithURL(_ URL: Any?) -> CGSize {

        var url: URL? = nil

        if (URL is URL) {

            url = URL as? URL

        }

        if (URL is String) {

            url = URL(string: URL as? String ?? "")

        }

        if URL == nil {

            return CGSize.zero

        }

        let imageSourceRef = CGImageSourceCreateWithURL(url as? CFURL?, nil)

        var width: CGFloat = 0

        var height: CGFloat = 0

        if imageSourceRef != nil {

            let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSourceRef, 0, nil)

            //以下是对手机32位、64位的处理（由网友评论区拿到的：小怪兽饲养猿）

            if imageProperties != nil {

                let widthNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelWidth)

#if __LP64__ && __LP64__

                if widthNumberRef != nil {

                    CFNumberGetValue(widthNumberRef, CFNumberType.float64Type, &width)

                }

                let heightNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight)

                if heightNumberRef != nil {

                    CFNumberGetValue(heightNumberRef, CFNumberType.float64Type, &height)

                }

#else

                if widthNumberRef != nil {

                    CFNumberGetValue(widthNumberRef, CFNumberType.float32Type, &width)

                }

                let heightNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight)

                if heightNumberRef != nil {

                    CFNumberGetValue(heightNumberRef, CFNumberType.float32Type, &height)

                }

#endif

            }

        }

        return CGSize(width: width, height: height)

    }

}