Speichern von Bild und laden es in Swift (iOS)

Dieser Funktion speichern Sie ein Bild in den Ordner "Dokumente":

func saveImage(image: UIImage) -> Bool {
    guard let data = UIImageJPEGRepresentation(image, 1) ?? UIImagePNGRepresentation(image) else {
        return false
    }
    guard let directory = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) as NSURL else {
        return false
    }
    do {
        try data.write(to: directory.appendingPathComponent("fileName.png")!)
        return true
    } catch {   
        print(error.localizedDescription)
        return false
    }
}

Zu verwenden:

let success = saveImage(image: UIImage(named: "image.png")!)

Diese Funktion erhalten Sie dieses Bild:

func getSavedImage(named: String) -> UIImage? {
    if let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) {
        return UIImage(contentsOfFile: URL(fileURLWithPath: dir.absoluteString).appendingPathComponent(named).path)
    }
    return nil
}

Zu verwenden:

if let image = getSavedImage(named: "fileName") {
    //do something with image
}

Details

• Xcode Version 10.2 (10E125), Swift 5

Lösung

//save
extension UIImage {

    func save(at directory: FileManager.SearchPathDirectory,
              pathAndImageName: String,
              createSubdirectoriesIfNeed: Bool = true,
              compressionQuality: CGFloat = 1.0)  -> URL? {
        do {
        let documentsDirectory = try FileManager.default.url(for: directory, in: .userDomainMask,
                                                             appropriateFor: nil,
                                                             create: false)
        return save(at: documentsDirectory.appendingPathComponent(pathAndImageName),
                    createSubdirectoriesIfNeed: createSubdirectoriesIfNeed,
                    compressionQuality: compressionQuality)
        } catch {
            print("-- Error: \(error)")
            return nil
        }
    }

    func save(at url: URL,
              createSubdirectoriesIfNeed: Bool = true,
              compressionQuality: CGFloat = 1.0)  -> URL? {
        do {
            if createSubdirectoriesIfNeed {
                try FileManager.default.createDirectory(at: url.deletingLastPathComponent(),
                                                        withIntermediateDirectories: true,
                                                        attributes: nil)
            }
            guard let data = jpegData(compressionQuality: compressionQuality) else { return nil }
            try data.write(to: url)
            return url
        } catch {
            print("-- Error: \(error)")
            return nil
        }
    }
}

//load from path

extension UIImage {
    convenience init?(fileURLWithPath url: URL, scale: CGFloat = 1.0) {
        do {
            let data = try Data(contentsOf: url)
            self.init(data: data, scale: scale)
        } catch {
            print("-- Error: \(error)")
            return nil
        }
    }
}

Nutzung

//save image (way 1)
let path = "photo/temp/album1/img.jpg"
guard   let img = UIImage(named: "img"),
        let url = img.save(at: .documentDirectory,
                           pathAndImageName: path) else { return }
print(url)

//get image from directory
guard let img2 = UIImage(fileURLWithPath: url) else { return }

//save image (way 2)
let tempDirectoryUrl = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(path)
guard let url2 = img2.save(at: tempDirectoryUrl) else { return }
print(url2)

Prüfergebnisse

öffnen Sie den iOS-simulator-Verzeichnis

Wenn Sie möchten, laden Bild vom server, die Sie tun können, wie unten

 let url = URL(string: "http://live-wallpaper.net/iphone/img/app/i/p/iphone-4s-wallpapers-mobile-backgrounds-dark_2466f886de3472ef1fa968033f1da3e1_raw_1087fae1932cec8837695934b7eb1250_raw.jpg")
        URLSession.shared.dataTask(with: url!) { (data, response, error) in
            guard
                let httpURLResponse = response as? HTTPURLResponse, httpURLResponse.statusCode == 200,
                let mimeType = response?.mimeType, mimeType.hasPrefix("image"),
                let data = data, error == nil
                else { return }
                DispatchQueue.main.async() { () -> Void in
                let fileManager = FileManager.default
                let paths = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent("apple.jpg")
                print(paths)
                fileManager.createFile(atPath: paths as String, contents: data, attributes: nil)

            }}.resume()

Müssen Sie ein Verzeichnis erstellen, in das Dokumente-Verzeichnis zum speichern einer Datei.

Fand ich die Lösung auf StackOverFlow vor einiger Zeit. Ich habe mich nicht erinnern, den Autor

Vorausgesetzt yourImage ist UIImage()

let ciImage = yourImage!.ciImage
let context = CIContext()
let cgImage = context.createCGImage(ciImage!, from: ciImage!.extent)
let uiImage = UIImage(cgImage: cgImage!)

UIImageWriteToSavedPhotosAlbum(uiImage, self, 
#selector(self.image(_:didFinishSavingWithError:contextInfo:)), nil)

und diese Funktion

@objc func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
if let error = error {
    //we got back an error!
    let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
    ac.addAction(UIAlertAction(title: "OK", style: .default))
    present(ac, animated: true)
} else {
    let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
    ac.addAction(UIAlertAction(title: "OK", style: .default))
    present(ac, animated: true)
}

}