如何在Swift中获取图像文件大小？

Question

我在用

UIImagePickerControllerDelegate,
UINavigationControllerDelegate,
UIPopoverControllerDelegate

这些代表从我的画廊或我的相机中选择图像.那么,如何在选择图像后获得图像文件大小？

我想用这个:

let filePath = "your path here"
    var fileSize : UInt64 = 0

    do {
        let attr : NSDictionary? = try NSFileManager.defaultManager().attributesOfItemAtPath(filePath)

        if let _attr = attr {
            fileSize = _attr.fileSize();
            print(fileSize)
        }
    } catch {
    }

但是在这里我需要一条路径,但是如果没有路径,我只能通过图像文件获得？

Answer 1

    guard let aStrUrl = Bundle.main.path(forResource: "1", ofType: "png") else { return }

   let aUrl = URL(fileURLWithPath: aStrUrl)
   print("Img size = \((Double(aUrl.fileSize) / 1000.00).rounded()) KB")

   extension URL {
        var attributes: [FileAttributeKey : Any]? {
            do {
                return try FileManager.default.attributesOfItem(atPath: path)
            } catch let error as NSError {
                print("FileAttribute error: \(error)")
            }
            return nil
        }

        var fileSize: UInt64 {
            return attributes?[.size] as? UInt64 ?? UInt64(0)
        }

        var fileSizeString: String {
            return ByteCountFormatter.string(fromByteCount: Int64(fileSize), countStyle: .file)
        }

        var creationDate: Date? {
            return attributes?[.creationDate] as? Date
        }
    }

Answer 2

extension UIImage {

    public enum DataUnits: String {
        case byte, kilobyte, megabyte, gigabyte
    }

    func getSizeIn(_ type: DataUnits)-> String {

        guard let data = self.pngData() else {
            return ""
        }

        var size: Double = 0.0

        switch type {
        case .byte:
            size = Double(data.count)
        case .kilobyte:
            size = Double(data.count) / 1024
        case .megabyte:
            size = Double(data.count) / 1024 / 1024
        case .gigabyte:
            size = Double(data.count) / 1024 / 1024 / 1024
        }

        return String(format: "%.2f", size)
    }
}

用法示例： print("Image size \(yourImage.getSizeIn(.megabyte)) mb")

Answer 3

迅捷3/4:

if let imageData = UIImagePNGRepresentation(image) {
     let bytes = imageData.count
     let kB = Double(bytes) / 1000.0 // Note the difference
     let KB = Double(bytes) / 1024.0 // Note the difference
}

请注意kB和KB之间的差异.回答这里,因为在我的情况下,我们有一个问题,而我们认为千字节为1024字节,但服务器端认为它是1000字节,这引起了一个问题.链接了解更多信息.

PS.几乎可以肯定你会使用kB(1000).