swift - 在 imagePicker 前面显示 View

Question

在我的应用程序中，用户可以打开相机胶卷选择一张照片，也可以打开相机直接自己拍摄一张照片。

在这两种情况下，选择/拍摄的图片也将保存在本地以供进一步引用。

缺点是保存操作通常会卡住屏幕直到完成。

我找到了一个动画in this post我想将其显示在 imagePickerController 前面，但我无法做到这一点。

class SinglePageViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate, UITextFieldDelegate, UINavigationBarDelegate {

    var spinner: UIActivityIndicatorView?

    lazy var showCameraImagePickerController: UIImagePickerController = {
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .camera
        imagePicker.allowsEditing = false
        return imagePicker
    }()

    lazy var showPhotoImagePickerController: UIImagePickerController = {
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .photoLibrary
        imagePicker.allowsEditing = false
        return imagePicker
    }()

    @IBOutlet weak var photoButton: UIButton!
    @IBAction func onPhotoButton(_ sender: Any) {
        self.present(self.showCameraImagePickerController, animated: true, completion: nil)
    }

    @IBOutlet weak var galleryButton: UIButton!
    @IBAction func onGalleryButton(_ sender: Any) {
        self.present(self.showPhotoImagePickerController, animated: true, completion: nil)
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        picker.dismiss(animated: true, completion: nil)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String: Any]) {

        //start animation
        let screenSize: CGRect = UIScreen.main.bounds

        spinner = UIActivityIndicatorView(frame: CGRect(x: screenSize.width / 2 - 150, y: screenSize.height / 2 - 150, width: 300, height: 300))
        spinner?.isHidden = false
        spinner?.startAnimating()
        spinner?.color = UIColor.red

        switch picker {
        case showCameraImagePickerController:
            // snap pic, save to doc, save to album

            self.showCameraImagePickerController.view.addSubview(spinner!)

            timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: false, block: { _ in

                let image = info[UIImagePickerControllerOriginalImage] as? UIImage

                if self.saveImage(imageName: "\(self.titleLabel.text!).png", image: image) {
                    // additionally save to photo album
                    UIImageWriteToSavedPhotosAlbum(image!, self, #selector(self.image(_:didFinishSavingWithError:contextInfo:)), nil)

                    print("saved \(self.titleLabel.text!).png")

                    self.imageView.image = image
                }
            })

        case showPhotoImagePickerController:
            //switch pic, save to doc. no album

            self.showPhotoImagePickerController.view.addSubview(spinner!)

            timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: false, block: { _ in

                let image = info[UIImagePickerControllerOriginalImage] as? UIImage

                if self.saveImage(imageName: "\(self.titleLabel.text!).png", image: image) {

                    print("saved new \(self.titleLabel.text!).png")

                    self.imageView.image = image

                    self.spinner?.stopAnimating()
                    self.spinner?.removeFromSuperview()
                    self.spinner = nil

                    self.showPhotoImagePickerController.dismiss(animated: true, completion: nil)
                } else {
                    self.spinner?.stopAnimating()
                    self.spinner?.removeFromSuperview()
                    self.spinner = nil

                    self.showPhotoImagePickerController.dismiss(animated: true, completion: nil)
                }
            })

        default:
            return
        }

    }

    @objc func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {

        spinner?.stopAnimating()
        spinner?.removeFromSuperview()
        spinner = nil

        self.showCameraImagePickerController.dismiss(animated: true, completion: nil)
    }

    func saveImage(imageName: String, image: UIImage?) -> Bool {

        //create an instance of the FileManager
        let fileManager = FileManager.default

        //get the image path
        let imagePath = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent(imgDir + imageName)
        print(imagePath)

        //get the image we took with camera
        let image = rotateImage(image: image!)

        //get the PNG data for this image
        let data = UIImagePNGRepresentation(image)

        //store it in the document directory
        if fileManager.createFile(atPath: imagePath as String, contents: data, attributes: nil) {
            newItem?.image = true

            return true
        } else {
            print("error while saving")
            return false
        }
    }
}

如您所见，我尝试使用 bringSubView(toFront:) 以及 zPosition 但没有结果。

正在关注this similar question我查看了 cameraOverlayView 的文档但它说它仅在 imagePicker 以相机模式呈现时才有效，这并不包括我打开照片库时的情况

我最近还尝试使用一种解决方法，这意味着我尽快关闭 imagePickerController 并随后更新图像，但由于应用程序结构发生了一些变化，这不再是最佳选择。

编辑

为了让自己更清楚，我将再次说明我需要什么:在 imagePicker 的前面显示旋转动画，只要我点击照片来选择它，直到我完成保存，然后关闭 imagePicker。我不想首先关闭选择器，然后在主视图中显示微调器时保存。

编辑2使用答案中的新代码更新了代码。唯一的问题是，如果我不设置计时器，微调器只会在保存过程结束时短暂显示自己(使用断点检查)。这会导致在保存过程的几秒钟内没有动画，并且在关闭 imagePicker 之前仅在最后出现短暂的旋转器幻影。只需放置 0.1 秒的延迟就会立即触发旋转器，我会得到预期的行为(保存时的动画)。不知道为什么

Answer 1

请查看完整的示例，其中在保存图像时将显示微调器，保存完成后微调器将被删除。

    class ViewController: UIViewController {

    /// Image picker controller
    lazy var imagePickerController: UIImagePickerController  = {
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .photoLibrary;
        imagePicker.allowsEditing = false
        return imagePicker
    }()

    var spinner: UIActivityIndicatorView?

    @IBAction func imagePickerButton(_ sender: UIButton) {
        self.present(self.imagePickerController, animated: true, completion: nil)
    }
}

// MARK: ImagePicker Delegate to get the image picked by the user
extension ViewController: UINavigationControllerDelegate, UIImagePickerControllerDelegate {

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        //start animation
        let screenSize: CGRect = UIScreen.main.bounds
        spinner = UIActivityIndicatorView(frame: CGRect(x: screenSize.width/2 - 50, y: screenSize.height/2 - 50, width: 100, height: 100))
        spinner?.isHidden = false
        spinner?.startAnimating()
        spinner?.color = UIColor.black
        self.imagePickerController.view.addSubview(spinner!)

        let image = info[UIImagePickerControllerOriginalImage] as? UIImage
        UIImageWriteToSavedPhotosAlbum(image!, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)

    }

    @objc func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {

        spinner?.stopAnimating()
        spinner?.removeFromSuperview()
        spinner  = nil

        self.imagePickerController.dismiss(animated: true, completion: nil)

        if  error == nil {
            let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
            present(ac, animated: true)
        }
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        picker.dismiss(animated: true, completion: nil)
    }
}