ios - 图像不是从一个 VC 到另一个 VC

Question

图像不是从一个 VC 到另一个 VC。

问题是将它显示到主 UIViewController 中的 ImageView 。我已将所有内容正确连接到 Storyboard中。

点击here查看我的 Storyboard布局。

请注意我的一些不必要的代码已从两个 ViewController 类中删除。

这是我的第一个 UIViewController:

import UIKit

class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {

    var imagePicker: UIImagePickerController!

    @IBAction func editPhoto(_ sender: UIButton) {
        let ViewController2 = storyboard?.instantiateViewController(withIdentifier: "AddNewEaterySegue") as! ViewController2
        ViewController2.imageForEdit = imageView.image!
        print(imageView)
        print(imageView.image!)
        navigationController?.pushViewController(ViewController2, animated: true)
    }

    @IBOutlet weak var imageView: UIImageView! {
        didSet {
            imageView.contentMode = .scaleAspectFill
            imageView.clipsToBounds = true
        }
    }

}

这是我的第二个 UIViewController:

import UIKit

class ViewController2:  UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {

    var filter : CIFilter!
    var imageForEdit = UIImage()
    var imagePicker: UIImagePickerController!

    @IBOutlet weak var select: UISegmentedControl!
    @IBOutlet weak var imageLabel: UIImageView!
    @IBOutlet weak var textField: UITextField!

    @IBAction func saveButtonPressed(_ sender: UIImage) {
        if textField.text == "" {
            print("Не все поля заполнены")
        } else {


        }
        performSegue(withIdentifier: "unwindSegueFromViewController", sender: sender)
    }

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


    @IBAction func tappedEnter(_ sender: Any) {

        if textField.text?.isEmpty ?? true {
            return
        } else {
            if let texttxt = textField.text {

                let data = texttxt.data(using: .ascii, allowLossyConversion: false)

                if select.selectedSegmentIndex == 0
                {
                    filter = CIFilter(name: "CICode128BarcodeGenerator")
                } else {
                    filter = CIFilter(name: "CIQRCodeGenerator")
                }

                filter.setValue(data, forKey: "inputMessage")
                let transform = CGAffineTransform(scaleX: 5, y: 5)
                let image = UIImage(ciImage: filter.outputImage!.transformed(by: transform))
                imageLabel.image = image
            }
        }
    }
}

Answer 1

当您推送到 ViewController2 时，ViewController 中的 imageView 是空的。

您究竟在哪里为 imageView 设置图像？

在您的 Storyboard中，ViewController 中的 imageView 是空的，并且在 ViewController 中 imageView 的 didSet 方法中您还没有为 imageView 设置任何图像。

在 ViewController 中试试这个:

 @IBOutlet weak var imageView: UIImageView! {
    didSet {

        //Add a test image to your project.
        imageView.image = UIImage(named: "YOUR_TEST_IMAGE_NAME.jpeg")
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true

    }
}

编辑: 好吧，我想我对你的问题并不清楚。因此，为了将图像从“ViewController2”发送回“ViewController”，您可以使用多种方法，但我会采用的方法是使用 Protocols。

我以一种通用的方式完成了它，但您可以应用它来将任何类型的数据从一个 View Controller 发送回前一个 View Controller 。

在 ViewController 中试试这个:

import UIKit

protocol ImageViewProtocol{
     func sendImageToViewController(theImage: UIImage)
}

class ViewController: UIViewController, ImageViewProtocol {

    func sendImageToViewController(theImage: UIImage) {
        imageView.image = theImage
    }

    @IBOutlet weak var imageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let viewcontroller2 = storyboard?.instantiateViewController(withIdentifier: "viewcontroller2") as! ViewController2
        viewcontroller2.delegate = self
        self.navigationController?.pushViewController(viewcontroller2, animated: true)

    }

}

在 ViewController2 中试试这个:

import UIKit

class ViewController2: UIViewController {

    var delegate: ImageViewProtocol!

    @IBOutlet weak var barcodeImageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        barcodeImageView.image = UIImage(named: "test_image.jpg")

    }

    @IBAction func saveButtonAction(_ sender: Any) {
        delegate.sendImageToViewController(theImage: barcodeImageView.image!)
        self.navigationController?.popViewController(animated: true)
    }

}