Swift ImagePicker在AutoLayout约束上引发SIGNAL SIGABRT

Question

我正在Swift5中构建一个项目，我需要用户上传照片。 我已经到了用户可以打开ImagePicker并选择照片的程度，但每当他们选择图像并返回到原始VC时，我都会收到SIGNAL SIGABRT错误（在帖子底部）：

这是我以编程方式添加约束的地方：

func setupLayout(){
    imgView.topAnchor.constraint(equalTo: view.topAnchor, constant: 150).isActive = true
    imgView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
    imgView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
    imgView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
    imgView.heightAnchor.constraint(equalToConstant: 125).isActive = true

    topLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
    topLabel.topAnchor.constraint(equalTo: imgView.bottomAnchor, constant: 60).isActive = true
    topLabel.widthAnchor.constraint(equalTo: view.widthAnchor, constant: -50).isActive = true
    topLabel.heightAnchor.constraint(equalToConstant: 50).isActive = true
    topLabel.adjustsFontSizeToFitWidth = true

    inputBox.topAnchor.constraint(equalTo: topLabel.bottomAnchor, constant: 30).isActive = true
    inputBox.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
    inputBox.heightAnchor.constraint(equalToConstant: 50).isActive = true
    inputBox.widthAnchor.constraint(equalToConstant: 250).isActive = true

    btn.topAnchor.constraint(equalTo: inputBox.bottomAnchor, constant: 40).isActive = true
    btn.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true

    let navBarImageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 10, height: 10))
    navBarImageView.contentMode = .scaleAspectFit
    let navBarImage = UIImage(named: "bzaLogo")
    navBarImageView.image = navBarImage
    self.navigationController?.navigationItem.titleView = navBarImageView
}

我将图像设置在imageView上：

func didSelect(image: UIImage?) {
    self.imgView.image = image
    self.global.uploadFile(imageView: self.uploadIcon.imageView!)
}

我在哪里添加子视图：

override func viewDidLoad() {
    super.viewDidLoad()
    currentState = 0
    imgView.translatesAutoresizingMaskIntoConstraints = false
    topLabel.translatesAutoresizingMaskIntoConstraints = false
    inputBox.translatesAutoresizingMaskIntoConstraints = false
    btn.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(imgView)
    view.addSubview(topLabel)
    view.addSubview(inputBox)
    view.addSubview(btn)

    inputBox.addTarget(self, action: #selector(inputBoxClicked(textField:)), for: .touchDown)
    imagePicker = ImagePicker(presentationController: self, delegate: self)
    viewModel.state = currentState
    inputBox.delegate = self

    setupLayout()
}

以下是抛出的错误：

2019-06-12 13：22：16.635903-0600 bZa [39792：1836482] ***由于未捕获的异常'NSGenericException'而终止应用程序，原因：'无法使用锚点激活约束，因为它们没有共同的祖先。 约束或其锚点是否引用不同视图层次结构中的项目？ 这是非法的。

Answer 1

目前的问题是您在没有评论祖先的视图之间添加约束，因此请验证您是否添加

view.addSubview(imgView)  
view.addSubview(topLabel) 
view.addSubview(inputBox)
view.addSubview(btn)

也别忘了

imgView.translatesAutoresizingMaskIntoConstraints = false 
topLabel.translatesAutoresizingMaskIntoConstraints = false
inputBox.translatesAutoresizingMaskIntoConstraints = false
btn.translatesAutoresizingMaskIntoConstraints = false