Swift : 때때로 화면 멈춤 현재 컨텍스트를 통해 그림을 표시하는 ViewController 닫기

Question

다음과 같은 문제가 있습니다. 때때로 현재 화면 위에 그림을 표시하는 ViewController를 닫을 때 화면이 멈추는 경우.

누군가이 문제를 해결하는 방법에 대한 통찰력을 제공 할 수 있습니까?

내 코드의 샘플은 아래의 발견 :

수입 UIKit

클래스 ViewControllerCell : UICollectionViewCell {

override init(frame: CGRect) { 
    super.init(frame: frame) 

    backgroundColor = UIColor.white 

    addSubview(showPhotoButton) 

    showPhotoButton.leftAnchor.constraint(equalTo: leftAnchor, constant: 200).isActive = true 
    showPhotoButton.bottomAnchor.constraint(equalTo: topAnchor, constant: 160).isActive = true 
    showPhotoButton.heightAnchor.constraint(equalToConstant: 50).isActive = true 
    showPhotoButton.widthAnchor.constraint(equalToConstant: 70).isActive = true 

} 

required init?(coder aDecoder: NSCoder) { 
    fatalError("init(coder:) has not been implemented") 
} 


lazy var showPhotoButton: UIButton = { 
    let button = UIButton(type: .system) 
    button.translatesAutoresizingMaskIntoConstraints = false 
    button.setTitle("Show", for: .normal) 
    button.addTarget(self, action: #selector(showSale), for: .touchUpInside) 
    button.setTitleColor(UIColor(r: 120, g: 80, b: 255), for: .normal) 
    return button 
}() 


@objc func showSale() { 
    let popupViewController = PopupViewController() 
    popupViewController.modalPresentationStyle = .overCurrentContext 
    popupViewController.modalTransitionStyle = UIModalTransitionStyle.crossDissolve 
    window!.rootViewController?.present(PopupViewController, animated: true, completion: nil) 
} 

}

수입 UIKit을

클래스 SalePopupViewController : UIViewController에 {

override func viewDidLoad() { 
    view.backgroundColor = UIColor(white: 1, alpha: 0.60) 
    view.isOpaque = false 

    view.addSubview(rebateImage) 
    view.addSubview(dismissButton) 

    dismissButton.topAnchor.constraint(equalTo: view.topAnchor).isActive = true 
    dismissButton.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true 
    dismissButton.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true 
    dismissButton.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true 

    rebateImage.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true 
    rebateImage.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: -35).isActive = true 
    rebateImage.heightAnchor.constraint(equalToConstant: 290).isActive = true 
    rebateImage.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 1).isActive = true 


} 

let dismissButton: UIButton = { 
    let button = UIButton(type: .system) 
    button.addTarget(self, action: #selector(dismissPopup), for: .touchUpInside) 
    button.translatesAutoresizingMaskIntoConstraints = false 
    return button 
}() 

let rebateImage: UIImageView = { 
    let image = UIImageView() 
    image.translatesAutoresizingMaskIntoConstraints = false 
    image.layer.masksToBounds = false 
    image.layer.cornerRadius = 2 
    image.contentMode = .scaleAspectFill 
    image.clipsToBounds = true 
    image.image = UIImage(named: "SaleCostco") 
    return image 
}() 

@objc func dismissPopup() { 

    DispatchQueue.global(qos: .userInitiated).async { 
     DispatchQueue.main.async { 
      self.dismiss(animated: true, completion: nil) 
     } 
    } 


} 

}

Answer 1

비동기 코드는 이해가되지 않습니다. 전역 대기열로 보낸 다음 즉시 즉시 주 스레드로 돌아갑니다. 단순히이에 dismissPopup()의 구현을 변경해보십시오 :

@objc func dismissPopup() { 
    dismiss(animated: true, completion: nil) 
}