UIAlert 和视图控制器的错误

Bug with UIAlert and View Controller

我的 iOS 应用中 iPad 的默认值 Alert 有一个非常奇怪的错误。

我在上面有三个按钮:一个用于相机,第二个用于照片库,第三个是关闭按钮。警报用于选择照片。我遇到的问题有时是,当我单击该警报上的关闭按钮时,会执行此类代码:

let loginVC = self.storyboard?.instantiateViewController(withIdentifier: "LoginViewController") as! LoginPageViewController

我不确定这是否正是执行的代码,但它执行注销操作并将用户重定向到登录屏幕。

这是我的 Alert

代码
func showPopover(uiView: UIView) {
        let alertController = UIAlertController(title: nil, message: "Choose Photos", preferredStyle: .actionSheet)

        let defaultAction = UIAlertAction(title: "Camera", style: .default, handler: { (alert: UIAlertAction!) -> Void in
            self.view?.pickPhotoFromCamera()
        })

        let galleryAction = UIAlertAction(title: "Gallery", style: .default, handler: { (alert: UIAlertAction!) -> Void in
            self.view?.pickPhotoFromLibrary()
        })

        let cancelAction = UIAlertAction(title: "Cancel", style: .destructive, handler: { (alert: UIAlertAction!) -> Void in
            (self.view as? UIViewController)?.dismiss(animated: true, completion: nil)
        })

        alertController.addAction(defaultAction)
        alertController.addAction(galleryAction)
        alertController.addAction(cancelAction)

        if let popoverController = alertController.popoverPresentationController {
            popoverController.sourceView = uiView
            popoverController.sourceRect = CGRect(x: uiView.bounds.midX, y: uiView.bounds.midY, width: 0, height: 0)
            popoverController.permittedArrowDirections = []
        }
        (view as? UIViewController)?.tabBarController!.present(alertController, animated: true, completion: nil)
    }

如您所见,我在alert中的代码没有任何注销操作,但有时会发生这种情况。也许有人有类似的问题?这可能是什么原因?

如果您需要更多信息 - 让我知道。预先感谢您的帮助!

尝试

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

取消当前视图控制器的 cancelAction 中的问题。将其样式设置为不使用处理程序取消。

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

首先,您无需为 .cancel 类型的操作按钮编写任何代码即可关闭显示的警报视图控制器。其次,您可以只使用视图来呈现警报控制器,无需请求它的父级 (tabBarController) 来执行此操作。您在 .cancel 按钮中的代码关闭了登录控制器本身。

import UIKit

class LoginViewController: UIViewController {

  func showPopover(uiView: UIView) {

    let alertController = UIAlertController(title: nil, message: "Choose Photos", preferredStyle: .actionSheet)


    let defaultAction = UIAlertAction(title: "Camera", style: .default, handler: { (alert: UIAlertAction!) -> Void in
      self.pickPhotoFromCamera()
    })

    let galleryAction = UIAlertAction(title: "Gallery", style: .default, handler: { (alert: UIAlertAction!) -> Void in
      self.pickPhotoFromLibrary()
    })

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

    alertController.addAction(defaultAction)
    alertController.addAction(galleryAction)
    alertController.addAction(cancelAction)

    if let popoverController = alertController.popoverPresentationController {
      popoverController.sourceView = uiView
      popoverController.sourceRect = uiView.bounds
    }

    present(alertController, animated: true, completion: nil)

  }

  private func pickPhotoFromCamera() { }
  private func pickPhotoFromLibrary() { }

}