如何在 Swift 中保存从 UIImagePickerController 中选取的图像？

我正在构建一个应用程序，让用户从其照片库中选择图像。我正在使用这段代码来保存它。

func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
    imgPicker.dismissViewControllerAnimated(true, completion: nil)
    NSUserDefaults.standardUserDefaults().setValue(image, forKey: "bgImage")
}

func imagePickerControllerDidCancel(picker: UIImagePickerController) {
    imgPicker.dismissViewControllerAnimated(true, completion: nil)
}

我后来发现你不能用 NSUserDefaults 保存图像，但你可以保存所选图像的路径，保存它并使用“if let ...”加载它

但我不知道该怎么做（找到路径并保存）。这个想法是让用户选择视图背景图像，有点像 Whatsapp 的做法。

如果我错了并且您无法存储路径，是否有任何简单的方法可以在不使用在线服务器的情况下保存选取的图像？

您可以使用 NSUserDefaults 保存和检索它：

//Save image
let img = UIImage() //Change to be from UIPicker
let data = UIImagePNGRepresentation(img)
NSUserDefaults.standardUserDefaults().setObject(data, forKey: "myImageKey")
NSUserDefaults.standardUserDefaults().synchronize()

//Get image
if let imgData = NSUserDefaults.standardUserDefaults().objectForKey("myImageKey") as? NSData {
    let retrievedImg = UIImage(data: imgData)
}

或者，如果您愿意，您可以读取/写入文件：

//Save image
let img = UIImage() //Change to be from UIPicker
let data = UIImagePNGRepresentation(img)!
do {
    let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String
    try data.writeToFile("\(documentsPath)myImage", options: [])

} catch {
    print("Error")
}

//Get image
do {
    let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String
    let readData = try NSData(contentsOfFile: "\(documentsPath)myImage", options: [])
    let retreivedImage = UIImage(data: readData)
}
catch {
    print("Error")
}

Swift 3:

//Save image
let data = UIImagePNGRepresentation(pickedImage)!
do {
    let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
    try data.write(to: URL(string: "\(documentsPath)/myImage")!, options: .atomic)
} catch {
    print("Error")
}

//Get image
do {
    let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
    let readData = try Data(contentsOf: URL(string: "\(documentsPath)/myImage")!)
    let retreivedImage = UIImage(data: readData)
} catch {
    print("Error")
}