问题描述
我正在尝试将用户图像保存到 userDefaults,但我总是收到错误“线程 1:“尝试为键保存的图像插入非属性列表对象(函数)”这是我的代码
import UIKit
class productSelectionPage: UIViewController {
@IBOutlet weak var productimageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
// Save image
let image = UIImage(named: "user")
let imageData = UIImage.jpegData(image)
UserDefaults.standard.setValue(imageData,forKey: "savedImage")
}
@IBAction func offerButtonTapped(_ sender: UIButton) {
// present image
let imageData = UserDefaults.standard.object(forKey: "savedImage")
let image = UIImage(data: (imageData as! NSData) as Data)
productimageView.image = image
// crash
}
}
解决方法
尝试像这样使用 PropertyListEncoder() 和 Decoder:
func saveImage() {
guard let data = UIImage(named: "image").jpegData(compressionQuality: 0.5) else { return }
let encoded = try! PropertyListEncoder().encode(data)
UserDefaults.standard.set(encoded,forKey: "KEY")
}
func loadImage() {
guard let data = UserDefaults.standard.data(forKey: "KEY") else { return }
let decoded = try! PropertyListDecoder().decode(Data.self,from: data)
let image = UIImage(data: decoded)
}
,
如果您曾经使用过 firebase,您就会明白所有图像和视频都保存为数据而不是像素。
保存到 UserDefaults 时采用了类似的方法
// 存储图像数据
private func store(image: UIImage,forKey key: String,withStorageType storageType: StorageType) {
if let pngRepresentation = image.pngData() {
UserDefaults.standard.set(pngRepresentation,forKey: key)
}
}
// 检索图像数据并获取图像
要检索它,我们将获取图像数据
private func retrieveImage(forKey key: String,inStorageType storageType: StorageType) -> UIImage? {
if let imageData = UserDefaults.standard.object(forKey: key) as? Data,let image = UIImage(data: imageData) {
return image
}
}
}