UIAlertController和UIViewAlertForUnsatisfiableConstraints错误

Question

我昨天升级到Xcode 10.2，并开始使用Swift 5，当出现UIAlertController照片提示时会注意到此错误。我不记得在Xcode 10.1中看到过

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600001321e00 UIView:0x7fe1246070a0.width == - 16   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.

我读过此问题如何捕获UIViewAlertForUnsatisfiableConstraints？ 并能够将错误定位到我的位置UIAlertController（以红色突出显示）

这是我的代码：

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600001321e00 UIView:0x7fe1246070a0.width == - 16   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.

我试图UIAlertController通过在我的promptPhoto()方法内部使用此代码来设置宽度，但无济于事。

 @objc private func promptPhoto() {

    let prompt = UIAlertController(title: "Choose a Photo",
                                   message: "",
                                   preferredStyle: .actionSheet)

    let imagePicker = UIImagePickerController()
    imagePicker.delegate = self

    let camerAction = UIAlertAction(title: "Camera", style: .default) { _ in
      guard self.isCameraAccessible() else {
        self.showAlert(title: "Oops", message: "Camera is not available")
        return
      }
      imagePicker.sourceType = .camera
      imagePicker.allowsEditing = true
      self.present(imagePicker, animated: true)
    }

    let libraryAction = UIAlertAction(title: "Photo Library", style: .default) { _ in
      imagePicker.sourceType = .photoLibrary
      imagePicker.allowsEditing = true
      self.present(imagePicker, animated: true)
    }

    let cancelAction = UIAlertAction(title: "Cancel",
                                     style: .cancel,
                                     handler: nil)

    prompt.addAction(camerAction)
    prompt.addAction(libraryAction)
    prompt.addAction(cancelAction)

    present(prompt, animated: true) {
      // Prevent closing the prompt by touch up outside the prompt.
      prompt.view.superview?.subviews[0].isUserInteractionEnabled = false
    }

  }

有没有一种方法可以控制UIAlertController宽度，以便摆脱错误消息？

先感谢您。

Answer 1

这可能是一个 Xcode bug。苹果还没有修复这个问题。最新的 xcode 11.3.1 也发生了这个错误