为什么数据没有在视图控制器之间传递？ 迅捷3

Question

I have 2 text labels on one view controller and I want to connect the text from the labels to the corresponding UIButtons and UILabels on another View Controller.

Right now when I press on the "thisUploadPhoto" button it loads 2 screens of the next screen, instead of just one screen. If you could help me with that it would be great. Also, when I press the done and cancel buttons on the PhotoLabelViewController it gives me this error:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[tot.PhotoShareLabelViewController didTapDone:]: unrecognized selector sent to instance 0x7f8cecf5d0b0'

When it is supposed to print 'done'

I don't know why my code below isn't working on connecting the 2 view controllers together.

import UIKit

class PhotoShareViewController: UIViewController {
    @IBOutlet weak var imageView: UIImageView!
    @IBOutlet weak var contentTextView: UITextView!

    @IBOutlet weak var thatTextField: UITextField!
    @IBOutlet weak var thisTextField: UITextField!
    var presenter: PhotoShareModuleInterface!
    var image: UIImage!

    @IBAction func thisUploadPhoto(_ sender: Any) {
        if thisTextField.text != "" && thatTextField.text != ""
        {
            performSegue(withIdentifier: "segue", sender: self)
        }
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        var photoShareLabelViewController = segue.destination as! PhotoShareLabelViewController
        photoShareLabelViewController.thisString = thisTextField.text!
        photoShareLabelViewController.thatString = thatTextField.text!
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        imageView.image = image
    }

    override var prefersStatusBarHidden: Bool {
        return true
    }

    @IBAction func didTapCancel(_ sender: AnyObject) {
        presenter.cancel()
        presenter.pop()
    }

    @IBAction func didTapDone(_ sender: AnyObject) {
        guard let message = thatTextField.text, !message.isEmpty else {
            return
        }
        guard let messageOne = thisTextField.text, !messageOne.isEmpty else {
            return
        }

        presenter.finish(with: image, content:message)
        presenter.dismiss()
    }
}

extension PhotoShareViewController: PhotoShareViewInterface {
    var controller: UIViewController? {
        return self
    }
}

import UIKit

class PhotoShareLabelViewController: UIViewController {
    @IBOutlet weak var thisLabel: UILabel!
    @IBOutlet weak var thatLabel: UILabel!
    @IBOutlet weak var thisButton: UIButton!
    @IBOutlet weak var thatButton: UIButton!

    var thisCounter = 0
    var thatCounter = 0
    var presenter: PhotoShareModuleInterface!
    var image: UIImage!

    @IBAction func pressedThisButton(_ sender: Any) {
        thisCounter += 1

        print(thisCounter)
    }

    @IBAction func pressedThatButton(_ sender: Any) {
        thatCounter += 1

        print(thatCounter)
    }

    var thisString = String()
    var thatString = String()

    @IBAction func pressedButtonDone(_ sender: Any) {
        print("done")
    }

    @IBAction func pressedButtonCancel(_ sender: Any) {
        print("cancel")
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        thisLabel.text = thisString
        thisButton.setTitle(thisString, for: UIControlState.normal)
        thatLabel.text = thatString
        thatButton.setTitle(thatString, for: UIControlState.normal)
    }

}

Answer 1

The "Done" button is wired from Storyboard to call a method called didTapDone in PhotoShareLabelViewController . However, your didTapDone method is implemented in PhotoShareViewController . It's a different view controller.

To fix this, put the method implementation in the correct view controller. Then, select your "Done" button in the Storyboard and go to its "Connections Inspector" [see image below] and remove its current wrong connection. Then, wire it to the correct didTapDone method in the correct view controller.