Swift 将图像从一个视图控制器传递到另一个控制器会给出零

我正在尝试向预览控制器发送图像，如下所示。我的问题是，预览控制器中的

newImage

是

nil

代码如下：

FirstViewController

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    print("In here")
    if segue.identifier == "showImage" {

        let secondViewController = self.storyboard!.instantiateViewController(withIdentifier: "showImage") as! showImageController

        secondViewController.newImage =  UIImage(named: imageArray[0])

    }
}

@IBOutlet weak var imageHolder: UIImageView!
var newImage: UIImage!

override func viewDidLoad() {
    super.viewDidLoad()
    imageHolder.image = newImage
    // Do any additional setup after loading the view.
}

预览控制器

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    print("In here")
    if segue.identifier == "showImage" {

        let secondViewController = self.storyboard!.instantiateViewController(withIdentifier: "showImage") as! showImageController

        secondViewController.newImage =  UIImage(named: imageArray[0])

    }
}

@IBOutlet weak var imageHolder: UIImageView!
var newImage: UIImage!

override func viewDidLoad() {
    super.viewDidLoad()
    imageHolder.image = newImage
    // Do any additional setup after loading the view.
}

---

InstanceEviewController调用viewDidLoad（），这样在调用映像时就不会设置映像。将代码移动到viewWillExample（），它就会工作

您应该使用

segue.destination

而不是像这样创建一个新的

 override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

   print("In here")

   if segue.identifier == "showImage" {

        let next = segue.destination as! showImageController

        next.newImage =  UIImage(named: imageArray[0])

    }

 }