爲什麼不在視圖控制器之間傳遞數據？ Swift 3

Question

我在一個視圖控制器上有兩個文本標籤，我想將標籤中的文本連接到另一個視圖控制器上相應的UIButtons和UILabel。

現在，當我按下「thisUploadPhoto」按鈕時，它會加載下一個屏幕的兩個屏幕，而不是一個屏幕。如果你能幫助我，那會很好。此外，當我按下了PhotoLabelViewController的完成和取消按鈕，它給了我這個錯誤：

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

當它應該打印「完成」

我不知道爲什麼我的代碼如下ISN」無需將2個視圖控制器連接在一起。

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」按鈕被從故事板有線連接到呼叫中PhotoShareLabelViewController稱爲didTapDone方法。但是，您的didTapDone方法在PhotoShareViewController中執行。這是一個不同的視圖控制器。

要解決此問題，請將方法實現置於正確的視圖控制器中。然後，在故事板中選擇您的「完成」按鈕，然後轉到其「連接檢查器」[請參閱下圖]並刪除其當前錯誤的連接。然後，在正確的視圖控制器中將它連接到正確的didTapDone方法。