ios - 当 View 改变时变量变为零

Question

我的 ViewController - 我只是选择一个图像，然后更新 imageView。尽管如此，每当我离开 View 时，ImageView 都会回到“face-unknown”，因为 newImage 为零。

为什么变量 newImage 不记得 View 更改后的图像？

var newImage: UIImage!
@IBOutlet weak var imageView: UIImageView!
var imagePicker = UIImagePickerController()


override func viewDidLoad() {
    super.viewDidLoad()
    if((newImage == nil)){
        imageView.image = UIImage(named:"face-unknown")!
    }else{
        imageView.image = newImage
    }

}

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {

    if let possibleImage = info["UIImagePickerControllerEditedImage"] as? UIImage {
        imageView.image = resizeImage(possibleImage,newWidth: 150)
        newImage = resizeImage(possibleImage,newWidth: 150)
    } else if let possibleImage = info["UIImagePickerControllerOriginalImage"] as? UIImage {
        imageView.image = resizeImage(possibleImage,newWidth: 150)
        newImage = resizeImage(possibleImage,newWidth: 150)
    } else {
        return
    }

Answer 1

您的 imageView 又回到了“face-unknown”状态，因为 viewDidLoad() 方法仅被调用一次。不是因为你的 UIImage 为零。相反，尝试在 viewWillAppear() 方法中更新您的 UIImageView，它应该可以工作