How to display an activity indicator with text on iOS 8 with Swift?

Question

I wanna show, programmatically, an activity indicator with text, like the one in the Photos app (after editing and saving a picture). How can I do this?

Answer 1

Xcode 9.0 • Swift 4.0

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import UIKit class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {     @IBOutlet weak var imageView: UIImageView!     @IBOutlet weak var filterButton: UIButton!     @IBOutlet weak var saveButton: UIButton!     let destinationUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!         .appendingPathComponent("filteredImage.png")     let imagePicker = UIImagePickerController()     let messageFrame = UIView()     var activityIndicator = UIActivityIndicatorView()     var strLabel = UILabel()     let effectView = UIVisualEffectView(effect: UIBlurEffect(style: .dark))     func activityIndicator(_ title: String) {         strLabel.removeFromSuperview()         activityIndicator.removeFromSuperview()         effectView.removeFromSuperview()         strLabel = UILabel(frame: CGRect(x: 50, y: 0, width: 160, height: 46))         strLabel.text = title         strLabel.font = .systemFont(ofSize: 14, weight: .medium)         strLabel.textColor = UIColor(white: 0.9, alpha: 0.7)         effectView.frame = CGRect(x: view.frame.midX - strLabel.frame.width/2, y: view.frame.midY - strLabel.frame.height/2 , width: 160, height: 46)         effectView.layer.cornerRadius = 15         effectView.layer.masksToBounds = true         activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .white)         activityIndicator.frame = CGRect(x: 0, y: 0, width: 46, height: 46)         activityIndicator.startAnimating()         effectView.contentView.addSubview(activityIndicator)         effectView.contentView.addSubview(strLabel)         view.addSubview(effectView)     }     func saveImage() {         do {             try imageView.image?.data?.write(to: destinationUrl, options: .atomic)             print("file saved")         } catch {             print(error)         }     }             func applyFilterToImage() {         imageView.image = imageView.image?.applying(contrast: 1.5)     }     override func viewDidLoad() {         super.viewDidLoad()         guard let url = URL(string: "https://upload.wikimedia.org/wikipedia/commons/a/a8/VST_images_the_Lagoon_Nebula.jpg"), let data = try? Data(contentsOf: url), let image = UIImage(data: data) else { return }         view.backgroundColor = UIColor(white: 0, alpha: 1)         imageView.image = image     }     @IBAction func startSavingImage(_ sender: AnyObject) {         saveButton.isEnabled = false         filterButton.isEnabled = false         activityIndicator("Saving Image")         DispatchQueue.main.async {             self.saveImage()             DispatchQueue.main.async {                 self.effectView.removeFromSuperview()                 self.saveButton.isEnabled = true                 self.filterButton.isEnabled = true             }         }     }     @IBAction func filterAction(_ sender: AnyObject) {         filterButton.isEnabled = false         saveButton.isEnabled = false         activityIndicator("Applying Filter")         DispatchQueue.main.async {             self.applyFilterToImage()             DispatchQueue.main.async {                 self.effectView.removeFromSuperview()                 self.filterButton.isEnabled = true                 self.saveButton.isEnabled = true             }         }     }     @IBAction func cameraAction(_ sender: AnyObject) {         if UIImagePickerController.isSourceTypeAvailable(.camera) {             imagePicker.delegate = self             imagePicker.sourceType = .camera             present(imagePicker, animated: true)         }     }     func imagePickerController(_ picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [AnyHashable: Any]!) {         dismiss(animated: true, completion: nil)         imageView.image = image     } } 

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extension Data {     var image: UIImage? { return UIImage(data: self) } } 

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extension UIImage {     var data: Data? { return UIImagePNGRepresentation(self) }     func applying(contrast value: NSNumber) -> UIImage? {         guard let ciImage = CIImage(image: self)?.applyingFilter("CIColorControls", withInputParameters: [kCIInputContrastKey: value]) else { return nil }         UIGraphicsBeginImageContextWithOptions(size, false, scale)         defer { UIGraphicsEndImageContext() }         UIImage(ciImage: ciImage).draw(in: CGRect(origin: .zero, size: size))         return UIGraphicsGetImageFromCurrentImageContext()     } } 

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