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[基本解决]在单独的vc中去presentViewController显示UIAlertController后无法让其消失

iOS crifan 841浏览 0评论

之前关于UIAlertController,可以在viewWillAppear中去presentViewController,并在最后去消失了:

[已解决]swift中给已有的ViewController中添加UIAlertAction并直接显示和正常消失返回被调用者视图

但是,后来单独抽出来对应的vc:

ImagePickerViewController

后,还是类似的代码:

class ImagePickerViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
   override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        let selectPictureAlertController = UIAlertController(title: “提示”, message: “”, preferredStyle: UIAlertControllerStyle.ActionSheet)
        let cancelAlertAction = UIAlertAction(title: “取消”, style: .Cancel, handler: self.cancelImagePick(_:))
        selectPictureAlertController.addAction(cancelAlertAction)
        let localAlbumAlertAction = UIAlertAction(title: “打开本地相册”, style: UIAlertActionStyle.Default, handler:self.openLocalAlbum(_:))
        selectPictureAlertController.addAction(localAlbumAlertAction)
        let openCameraAlertAction = UIAlertAction(title: “打开相机”, style: UIAlertActionStyle.Default, handler: self.openCamera(_:))
        selectPictureAlertController.addAction(openCameraAlertAction)
        selectPictureAlertController.modalPresentationStyle = .Custom
        self.presentViewController(selectPictureAlertController, animated: true, completion: nil)
    }

然后最后去让此UIAlertController去消失:

结果试了各种代码:

    func dissmissCurrentVC() {
        gLog.verbose(“”)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x7be90330>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7becccf0>), self.presentedViewController=Optional(<UIImagePickerController: 0x7c168c00>), self.presentingViewController=Optional(<UINavigationController: 0x7a9a1800>)
        self.dismissViewControllerAnimated(false, completion: {
            gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
            //self=<Sales_App.ImagePickerViewController: 0x7be90330>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7becccf0>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7a9a1800>)
//            if self.pickImageCompletionHandler != nil {
//                self.pickImageCompletionHandler!(pickedImage: self.pickedImage)
//            }
            if self.presentedViewController != nil {
                self.dismissViewControllerAnimated(false, completion: nil)
            }
            //self.selectPictureAlertController.dismissViewControllerAnimated(false, completion: nil)
//            if self.parentVC != nil {
//                gLog.verbose(“self.parentVC.presentedViewController=\(self.parentVC!.presentedViewController)”)
//                //self.parentVC.presentedViewController=Optional(<Sales_App.ImagePickerViewController: 0x12faa2370>)
//
//                if self.parentVC!.presentedViewController != nil {
//                    self.parentVC!.dismissViewControllerAnimated(false, completion: nil)
//                }
//            }
        })
    }

都没用。

去viewWillAppear:

        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x7df92970>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7deb2e20>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7c27c400>)
        self.presentViewController(selectPictureAlertController, animated: true, completion: nil)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x7df92970>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7deb2e20>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7c27c400>)

和之后的代码调试发现:

    func openLocalAlbum(alerAction:UIAlertAction){
        gLog.verbose(“alerAction=\(alerAction)”)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x7df92970>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7deb2e20>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7c27c400>)
        let imagePicker:UIImagePickerController = UIImagePickerController()
        gLog.verbose(“imagePicker=\(imagePicker)”)
        imagePicker.delegate = self
        self.presentViewController(imagePicker, animated: true, completion: nil)
    }

之前的UIAlertController,按照到底应该是当前的:

self.presentedViewController

但是实际上此处却是:

self.presentedViewController=nil

inside viewcontroller show UIAlertController and dismiss

objective c – Presenting a UIAlertController from a modally presented controller that is being dismissed – Stack Overflow

ios – show UIAlertController outside of ViewController – Stack Overflow

ios – How to dismiss an UIAlertController and the keyboard simultaneously? – Stack Overflow

uikit – Presenting a view controller modally from an action sheet’s delegate in iOS8/iOS9 – Stack Overflow

改为:

        dispatchMain_async({
            self.presentViewController(selectPictureAlertController, animated: true, completion: nil)
            gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
            //self=<Sales_App.ImagePickerViewController: 0x7df92970>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7deb2e20>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7c27c400>)
        })

试试,结果问题依旧。

viewcontroller show UIAlertController

ios – What is the best way to check if a UIAlertController is already presenting? – Stack Overflow

Swift: “Attempt to present UIAlertController on ViewController whose view is not in the window hierarchy!”

去移动到viewDidAppear试试

(注:之前就没去打算放在viewDidAppear,因为:想要这个UIAlertController尽快的显示,所以放在viewWillAppear比在viewDidAppear更快能显示)

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        let selectPictureAlertController = UIAlertController(title: “提示”, message: “”, preferredStyle: UIAlertControllerStyle.ActionSheet)
        let cancelAlertAction = UIAlertAction(title: “取消”, style: .Cancel, handler: self.cancelImagePick(_:))
        selectPictureAlertController.addAction(cancelAlertAction)
        let localAlbumAlertAction = UIAlertAction(title: “打开本地相册”, style: UIAlertActionStyle.Default, handler:self.openLocalAlbum(_:))
        selectPictureAlertController.addAction(localAlbumAlertAction)
        let openCameraAlertAction = UIAlertAction(title: “打开相机”, style: UIAlertActionStyle.Default, handler: self.openCamera(_:))
        selectPictureAlertController.addAction(openCameraAlertAction)
        selectPictureAlertController.modalPresentationStyle = .Custom
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
        self.presentViewController(selectPictureAlertController, animated: true, completion: nil)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
    }

问题依旧:

self.presentedViewController还是nil

但是,最后去用两次的dismissViewControllerAnimated去消失掉UIAlertController,则是可以的:

    func dissmissCurrentVC() {
        gLog.verbose(“”)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x7be90330>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7becccf0>), self.presentedViewController=Optional(<UIImagePickerController: 0x7c168c00>), self.presentingViewController=Optional(<UINavigationController: 0x7a9a1800>)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=Optional(<UIImagePickerController: 0x7a454e00>), self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
        self.dismissViewControllerAnimated(false, completion: {
            gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
            //self=<Sales_App.ImagePickerViewController: 0x7be90330>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7becccf0>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7a9a1800>)
            //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=Optional(<UIAlertController: 0x7ab89c00>), self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
//            if self.pickImageCompletionHandler != nil {
//                self.pickImageCompletionHandler!(pickedImage: self.pickedImage)
//            }
            if self.presentedViewController != nil {
                self.dismissViewControllerAnimated(false, completion: nil)
            }
            //self.selectPictureAlertController.dismissViewControllerAnimated(false, completion: nil)
//            if self.parentVC != nil {
//                gLog.verbose(“self.parentVC.presentedViewController=\(self.parentVC!.presentedViewController)”)
//                //self.parentVC.presentedViewController=Optional(<Sales_App.ImagePickerViewController: 0x12faa2370>)
//
//                if self.parentVC!.presentedViewController != nil {
//                    self.parentVC!.dismissViewControllerAnimated(false, completion: nil)
//                }
//            }
        })
    }

期间的顺序是:

1.先是:self.dismissViewControllerAnimated

2.然后是:

(此时:self.presentedViewController=nil)

viewDidAppear中的,self.presentViewController

(此时:self.presentedViewController=Optional(<UIAlertController: 0x7ab89c00>))

-》此处会导致界面上,出现了选择相册还是照相机的界面,一闪而过

-》会让用户觉得很不爽

3.最后是:

          if self.presentedViewController != nil {
                self.dismissViewControllerAnimated(false, completion: nil)
            }

-》总的说就是:

虽然可以实现:

通过两次的self.dismissViewControllerAnimated

最后能让UIAlertController消失掉

但是还是会有一闪而过的问题

-》

可以去viewDidAppear中加判断,如果当前的selectPictureAlertController有值了,就不再显示

也是可以解决问题的,但是总觉得不够正规

UIViewController presentViewController UIAlertController

UIViewController dismiss UIAlertController

最后无奈,还是用笨办法,就是用刚才非正规的办法,去实现:

当已经添加了UIAlertController的action后,就可以了。

最终代码是:

class ImagePickerViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    var selectPictureAlertController:UIAlertController
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.clearColor()
    }
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
    }
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //
        guard self.selectPictureAlertController.actions.isEmpty else {
            gLog.verbose(“already added alert actions”)
            return
        }
        self.selectPictureAlertController = UIAlertController(title: “提示”, message: “”, preferredStyle: UIAlertControllerStyle.ActionSheet)
        let cancelAlertAction = UIAlertAction(title: “取消”, style: .Cancel, handler: self.cancelImagePick(_:))
        selectPictureAlertController.addAction(cancelAlertAction)
        let localAlbumAlertAction = UIAlertAction(title: “打开本地相册”, style: UIAlertActionStyle.Default, handler:self.openLocalAlbum(_:))
        selectPictureAlertController.addAction(localAlbumAlertAction)
        let openCameraAlertAction = UIAlertAction(title: “打开相机”, style: UIAlertActionStyle.Default, handler: self.openCamera(_:))
        selectPictureAlertController.addAction(openCameraAlertAction)
        selectPictureAlertController.modalPresentationStyle = .Custom
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
        self.presentViewController(selectPictureAlertController, animated: true, completion: nil)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=Optional(<UIAlertController: 0x7ab89c00>), self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
    }
    func dissmissCurrentVC() {
        gLog.verbose(“”)
        gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
        //self=<Sales_App.ImagePickerViewController: 0x7be90330>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7becccf0>), self.presentedViewController=Optional(<UIImagePickerController: 0x7c168c00>), self.presentingViewController=Optional(<UINavigationController: 0x7a9a1800>)
        //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=Optional(<UIImagePickerController: 0x7a454e00>), self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
        self.dismissViewControllerAnimated(false, completion: {
            gLog.verbose(“self=\(self), self.parentViewController=\(self.parentViewController), self.presentationController=\(self.presentationController), self.presentedViewController=\(self.presentedViewController), self.presentingViewController=\(self.presentingViewController)”)
            //self=<Sales_App.ImagePickerViewController: 0x7be90330>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x7becccf0>), self.presentedViewController=nil, self.presentingViewController=Optional(<UINavigationController: 0x7a9a1800>)
            //self=<Sales_App.ImagePickerViewController: 0x797567f0>, self.parentViewController=nil, self.presentationController=Optional(<UIPresentationController: 0x79759d10>), self.presentedViewController=Optional(<UIAlertController: 0x7ab89c00>), self.presentingViewController=Optional(<UINavigationController: 0x7b31d000>)
//            if self.presentedViewController != nil {
                self.dismissViewControllerAnimated(false, completion: nil)
//            }
            if self.pickImageCompletionHandler != nil {
                self.pickImageCompletionHandler!(pickedImage: self.pickedImage)
            }
            //self.selectPictureAlertController.dismissViewControllerAnimated(false, completion: nil)
//            if self.parentVC != nil {
//                gLog.verbose(“self.parentVC.presentedViewController=\(self.parentVC!.presentedViewController)”)
//                //self.parentVC.presentedViewController=Optional(<Sales_App.ImagePickerViewController: 0x12faa2370>)
//
//                if self.parentVC!.presentedViewController != nil {
//                    self.parentVC!.dismissViewControllerAnimated(false, completion: nil)
//                }
//            }
        })
    }
}

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