根據圖片URL獲取圖片的尺寸【Swift語言實現】

import UIKit

extension UIImage {

    /// 獲取網路圖片尺寸

    ///

    /// - Parameter url: 網路圖片鏈接

    /// - Returns: 圖片尺寸size

    class func getImageSize(_ url: String?) -> CGSize {

        guard let urlStr = url else {

            return CGSize.zero

        }

        let tempUrl = URL(string: urlStr)

        let imageSourceRef = CGImageSourceCreateWithURL(tempUrl! as CFURL, nil)

        var width: CGFloat = 0

        var height: CGFloat = 0

        if let imageSRef = imageSourceRef {

            let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSRef, 0, nil)

            if let imageP = imageProperties {

                let imageDict = imageP as Dictionary

                width = imageDict[kCGImagePropertyPixelWidth] as! CGFloat

                height = imageDict[kCGImagePropertyPixelHeight] as! CGFloat

            }

        }

        return CGSize(width: width, height: height)

    }

}