如何在 Swift 中获取图像文件大小？

Question

我正在使用

UIImagePickerControllerDelegate,
UINavigationControllerDelegate,
UIPopoverControllerDelegate

这些代表用于从我的画廊或相机中选择图像。那么，选择图片后如何获取图片文件大小呢？

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 {
    }

但是这里我需要一个路径，但是没有路径我怎么能得到，只是通过图像文件呢？

Answer 1

请在 google 上查看 1 kb 到 1000 字节。

https://www.google.com/search?q=1+kb+%3D+how+many+bytes&oq=1+kb+%3D+how+many+bytes&aqs=chrome..69i57.8999j0j1&sourceid=chrome&ie=UTF-8

---

因此，在获得适当尺寸的同时，我通过在 App Bundle 中添加图像和在模拟器中的照片中添加了多个场景。 嗯，我从我的 Mac 上截取的图像是 299.0 KB。

---

场景 1： 将图像添加到应用程序包

在您的 Xcode 中添加图像时，图像的大小将在项目目录中保持不变。但是你从它的路径中得到它的大小会减少到 257.0 KB。这是设备或模拟器中使用的图像的实际大小。

    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
        }
    }

场景2：在模拟器中添加图片到照片

在模拟器或设备中向照片添加图像时，图像大小从 299.0 KB 增加到 393.0 KB。设备或模拟器的文档目录中存储的图片的实际大小。

Swift 4 及更早版本

var image = info[UIImagePickerControllerOriginalImage] as! UIImage
var imgData: NSData = NSData(data: UIImageJPEGRepresentation((image), 1)) 
// var imgData: NSData = UIImagePNGRepresentation(image) 
// you can also replace UIImageJPEGRepresentation with UIImagePNGRepresentation.
var imageSize: Int = imgData.count
print("size of image in KB: %f ", Double(imageSize) / 1000.0)

斯威夫特 5

let image = info[UIImagePickerController.InfoKey.originalImage] as! UIImage

let imgData = NSData(data: image.jpegData(compressionQuality: 1)!)
var imageSize: Int = imgData.count
print("actual size of image in KB: %f ", Double(imageSize) / 1000.0)   

通过添加 .rounded() 它将为您提供 393.0 KB，如果不使用它，它将为您提供 393.442 KB。因此，请使用上述代码手动检查图像大小。由于图像的大小在不同的设备和 mac 中可能会有所不同。我只在 mac mini 和模拟器 iPhone XS 上检查过。

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)
    }
}

使用示例：print("Image size \(yourImage.getSizeIn(.megabyte)) mb")

Answer 3

我解决了数据单位转换问题：

字节 -> KB -> MB -> GB -> ... -> 极限怪物数据

enum dataUnits:CaseIterable {
case B      //Byte
case KB     //kilobyte
case MB     //megabyte
case GB     //gigabyte
case TB     //terabyte
case PB     //petabyte
case EB     //exabyte
case ZB     //zettabyte
case YB     //yottabyte
case BD     //Big Data
case BBx    // Extra Big Bytes
case BBxx   // 2 time Extra Big Bytes
case BBxxx  // 3 time Extra Big Bytes
case BBxxxx // 4 time Extra Big Bytes
case MBB    // Monster Big Bytes 
}
func convertStorageUnit(data n:Double,inputDataUnit unitLevel:Int,roundPoint:Int = 2,nG:Double = 1000.0)->String{
if(n>=nG){
    return convertStorageUnit(data:n/1024,inputDataUnit:unitLevel+1) 
}else{
    let ut = unitLevel > dataUnits.allCases.count + 1 ? "Extreme Monster Data" : dataUnits.allCases.map{"\($0)"}[unitLevel]

   return "\(String(format:"%.\(roundPoint)f",n)) \(ut)"
}

}

print(
convertStorageUnit(data:99922323343439789798789898989897987945454545920,
inputDataUnit:dataUnits.allCases.firstIndex(of: .B)!,roundPoint: 0)
)

输出：8.87 PB

注意：输入数据长度应小于 64 位 或 根据数据类型更改数据类型

Answer 4

//斯威夫特4

if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
        ///check image Size
       let imgData = NSData(data: UIImageJPEGRepresentation((pickedImage), 1)!)
       let imageSize: Int = imgData.count
       print("size of image in KB: %f ", Double(imageSize) / 1024.0)
       print("size of image in MB: %f ", Double(imageSize) / 1024.0 / 1024)    

    }

Answer 5

试试这个代码 (Swift 4.2)

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
    }
}

并使用示例

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

        let aUrl = URL(fileURLWithPath: aStrUrl)

        print("Img size = \((Double(aUrl.fileSize) / 1000.00).rounded()) KB")

Answer 6

详情

• Xcode 10.2.1 (10E1001)、Swift 5

解决方案

extension String {
    func getNumbers() -> [NSNumber] {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        let charset = CharacterSet.init(charactersIn: " ,.")
        return matches(for: "[+-]?([0-9]+([., ][0-9]*)*|[.][0-9]+)").compactMap { string in
            return formatter.number(from: string.trimmingCharacters(in: charset))
        }
    }

    // https://stackoverflow.com/a/54900097/4488252
    func matches(for regex: String) -> [String] {
        guard let regex = try? NSRegularExpression(pattern: regex, options: [.caseInsensitive]) else { return [] }
        let matches  = regex.matches(in: self, options: [], range: NSMakeRange(0, self.count))
        return matches.compactMap { match in
            guard let range = Range(match.range, in: self) else { return nil }
            return String(self[range])
        }
    }
}

extension UIImage {
    func getFileSizeInfo(allowedUnits: ByteCountFormatter.Units = .useMB,
                         countStyle: ByteCountFormatter.CountStyle = .file) -> String? {
        // https://developer.apple.com/documentation/foundation/bytecountformatter
        let formatter = ByteCountFormatter()
        formatter.allowedUnits = allowedUnits
        formatter.countStyle = countStyle
        return getSizeInfo(formatter: formatter)
    }

    func getFileSize(allowedUnits: ByteCountFormatter.Units = .useMB,
                     countStyle: ByteCountFormatter.CountStyle = .memory) -> Double? {
        guard let num = getFileSizeInfo(allowedUnits: allowedUnits, countStyle: countStyle)?.getNumbers().first else { return nil }
        return Double(truncating: num)
    }

    func getSizeInfo(formatter: ByteCountFormatter, compressionQuality: CGFloat = 1.0) -> String? {
        guard let imageData = jpegData(compressionQuality: compressionQuality) else { return nil }
        return formatter.string(fromByteCount: Int64(imageData.count))
    }
}

用法

guard let image = UIImage(named: "img") else { return }
if let imageSizeInfo = image.getFileSizeInfo() {
    print("\(imageSizeInfo), \(type(of: imageSizeInfo))") // 51.9 MB, String
}

if let imageSizeInfo = image.getFileSizeInfo(allowedUnits: .useBytes, countStyle: .file) {
    print("\(imageSizeInfo), \(type(of: imageSizeInfo))") // 54,411,697 bytes, String
}

if let imageSizeInfo = image.getFileSizeInfo(allowedUnits: .useKB, countStyle: .decimal) {
    print("\(imageSizeInfo), \(type(of: imageSizeInfo))") // 54,412 KB, String
}

if let size = image.getFileSize() {
    print("\(size), \(type(of: size))") // 51.9, Double
}

Answer 7

斯威夫特 4.2

let jpegData = image.jpegData(compressionQuality: 1.0)
let jpegSize: Int = jpegData?.count ?? 0
print("size of jpeg image in KB: %f ", Double(jpegSize) / 1024.0)

Answer 8

let imageData = UIImageJPEGRepresentation(image, 1)
let imageSize = imageData?.count

UIImageJPEGRepresentation — 以 JPEG 格式返回指定图像的 Data 对象。值 1.0 表示最小压缩（接近原始图像）。

imageData?.count — 返回数据长度（字符数等于字节）。

重要！ UIImageJPEGRepresentation 或 UIImagePNGRepresentation 不会返回原始图像。但是如果使用给定的数据作为上传源 - 文件大小与服务器上的相同（即使使用压缩）。

Answer 9

let data = UIImageJPEGRepresentation(image, 1)
let imageSize = data?.count

How to get the size of a UIImage in KB? 的副本

Answer 10

斯威夫特 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 之间的区别。在这里回答是因为在我的情况下我们遇到了一个问题，我们将千字节视为 1024 字节，但服务器端将其视为 1000 字节，这导致了问题。 Link 了解更多。

PS。几乎可以肯定你会选择 kB (1000)。

Answer 11

斯威夫特 3

let uploadData = UIImagePNGRepresentation(image)
let array = [UInt8](uploadData)
print("Image size in bytes:\(array.count)")

Answer 12

let selectedImage = info[UIImagePickerControllerOriginalImage] as!  UIImage 
let selectedImageData: NSData = NSData(data:UIImageJPEGRepresentation((selectedImage), 1)) 
let selectedImageSize:Int = selectedImageData.length 
print("Image Size: %f KB", selectedImageSize /1024.0)

Answer 13

试试这个

import Darwin

...    

let size = malloc_size(&_attr)