为什么不在视图控制器之间传递数据？ Swift 3

Question

我在一个视图控制器上有两个文本标签，我想将标签中的文本连接到另一个视图控制器上相应的UIButtons和UILabel。

现在，当我按下“thisUploadPhoto”按钮时，它会加载下一个屏幕的两个屏幕，而不是一个屏幕。如果你能帮助我，那会很好。此外，当我按下了PhotoLabelViewController的完成和取消按钮，它给了我这个错误：

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

当它应该打印“完成”

我不知道为什么我的代码如下ISN”无需将2个视图控制器连接在一起。

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

“完成”按钮被从故事板有线连接到呼叫中PhotoShareLabelViewController称为didTapDone方法。但是，您的didTapDone方法在PhotoShareViewController中执行。这是一个不同的视图控制器。

要解决此问题，请将方法实现置于正确的视图控制器中。然后，在故事板中选择您的“完成”按钮，然后转到其“连接检查器”[请参阅下图]并删除其当前错误的连接。然后，在正确的视图控制器中将它连接到正确的didTapDone方法。