Swift - UIImagePickerController - how to use it? - ios

Question

I am trying hard to understand how this works, but it's pretty hard for me. =)
I have 1 view, there is one button and one small ImageView area for preview.
The button triggers imagepickercontroller, and the UIView will display picked image.
There is no error but the image doesn't show in the UIImageView area.
var imagePicker = UIImagePickerController()
#IBOutlet var imagePreview : UIImageView
#IBAction func AddImageButton(sender : AnyObject) {
imagePicker.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
imagePicker.delegate = self
self.presentModalViewController(imagePicker, animated: true)
}
func imagePickerController(picker: UIImagePickerController!, didFinishPickingMediaWithInfo info:NSDictionary!) {
var tempImage:UIImage = info[UIImagePickerControllerOriginalImage] as UIImage
imagePreview.image = tempImage
self.dismissModalViewControllerAnimated(true)
}
func imagePickerControllerDidCancel(picker: UIImagePickerController!) {
self.dismissModalViewControllerAnimated(true)
}

Answer 1

You're grabbing a UIImage named UIImagePickerControllerOriginalImage and there exists no such image. You're meant to grab the UIImage with the key UIImagePickerControllerOriginalImage from the editingInfo dictionary:
let tempImage = editingInfo[UIImagePickerControllerOriginalImage] as! UIImage

Answer 2

Details
Xcode 11.4.1 (11E503a), Swift 5.2
More
How to build own photo picker
Solution
import UIKit
import AVFoundation
import Photos
protocol ImagePickerDelegate: class {
func imagePicker(_ imagePicker: ImagePicker, grantedAccess: Bool,
to sourceType: UIImagePickerController.SourceType)
func imagePicker(_ imagePicker: ImagePicker, didSelect image: UIImage)
func cancelButtonDidClick(on imageView: ImagePicker)
}
class ImagePicker: NSObject {
private weak var controller: UIImagePickerController?
weak var delegate: ImagePickerDelegate? = nil
func dismiss() { controller?.dismiss(animated: true, completion: nil) }
func present(parent viewController: UIViewController, sourceType: UIImagePickerController.SourceType) {
let controller = UIImagePickerController()
controller.delegate = self
controller.sourceType = sourceType
self.controller = controller
DispatchQueue.main.async {
viewController.present(controller, animated: true, completion: nil)
}
}
}
// MARK: Get access to camera or photo library
extension ImagePicker {
private func showAlert(targetName: String, completion: ((Bool) -> Void)?) {
DispatchQueue.main.async { [weak self] in
guard let self = self else { return }
let alertVC = UIAlertController(title: "Access to the \(targetName)",
message: "Please provide access to your \(targetName)",
preferredStyle: .alert)
alertVC.addAction(UIAlertAction(title: "Settings", style: .default, handler: { action in
guard let settingsUrl = URL(string: UIApplication.openSettingsURLString),
UIApplication.shared.canOpenURL(settingsUrl) else { completion?(false); return }
UIApplication.shared.open(settingsUrl, options: [:]) { [weak self] _ in
self?.showAlert(targetName: targetName, completion: completion)
}
}))
alertVC.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { _ in completion?(false) }))
UIApplication.shared.windows.filter { $0.isKeyWindow }.first?
.rootViewController?.present(alertVC, animated: true, completion: nil)
}
}
func cameraAsscessRequest() {
if delegate == nil { return }
let source = UIImagePickerController.SourceType.camera
if AVCaptureDevice.authorizationStatus(for: .video) == .authorized {
delegate?.imagePicker(self, grantedAccess: true, to: source)
} else {
AVCaptureDevice.requestAccess(for: .video) { [weak self] granted in
guard let self = self else { return }
if granted {
self.delegate?.imagePicker(self, grantedAccess: granted, to: source)
} else {
self.showAlert(targetName: "camera") { self.delegate?.imagePicker(self, grantedAccess: $0, to: source) }
}
}
}
}
func photoGalleryAsscessRequest() {
PHPhotoLibrary.requestAuthorization { [weak self] result in
guard let self = self else { return }
let source = UIImagePickerController.SourceType.photoLibrary
if result == .authorized {
DispatchQueue.main.async { [weak self] in
guard let self = self else { return }
self.delegate?.imagePicker(self, grantedAccess: result == .authorized, to: source)
}
} else {
self.showAlert(targetName: "photo gallery") { self.delegate?.imagePicker(self, grantedAccess: $0, to: source) }
}
}
}
}
// MARK: UINavigationControllerDelegate
extension ImagePicker: UINavigationControllerDelegate { }
// MARK: UIImagePickerControllerDelegate
extension ImagePicker: UIImagePickerControllerDelegate {
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let image = info[.editedImage] as? UIImage {
delegate?.imagePicker(self, didSelect: image)
return
}
if let image = info[.originalImage] as? UIImage {
delegate?.imagePicker(self, didSelect: image)
} else {
print("Other source")
}
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
delegate?.cancelButtonDidClick(on: self)
}
}
Full Usage
Info.plist
<key>NSPhotoLibraryUsageDescription</key>
<string>bla-bla-bla</string>
<key>NSCameraUsageDescription</key>
<string>bla-bla-bla</string>
ViewController (do not forget to paste solution code)
import UIKit
class ViewController: UIViewController {
private weak var imageView: UIImageView!
private lazy var imagePicker: ImagePicker = {
let imagePicker = ImagePicker()
imagePicker.delegate = self
return imagePicker
}()
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.leftBarButtonItem = UIBarButtonItem(title: "camera", style: .plain, target: self,
action: #selector(cameraButtonTapped))
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "photo", style: .plain, target: self,
action: #selector(photoButtonTapped))
let imageView = UIImageView(frame: CGRect(x: 40, y: 80, width: 200, height: 200))
imageView.backgroundColor = .lightGray
view.addSubview(imageView)
self.imageView = imageView
}
#objc func photoButtonTapped(_ sender: UIButton) { imagePicker.photoGalleryAsscessRequest() }
#objc func cameraButtonTapped(_ sender: UIButton) { imagePicker.cameraAsscessRequest() }
}
// MARK: ImagePickerDelegate
extension ViewController: ImagePickerDelegate {
func imagePicker(_ imagePicker: ImagePicker, didSelect image: UIImage) {
imageView.image = image
imagePicker.dismiss()
}
func cancelButtonDidClick(on imageView: ImagePicker) { imagePicker.dismiss() }
func imagePicker(_ imagePicker: ImagePicker, grantedAccess: Bool,
to sourceType: UIImagePickerController.SourceType) {
guard grantedAccess else { return }
imagePicker.present(parent: self, sourceType: sourceType)
}
}
Images

Answer 3

import MobileCoreServices
class SecondViewController: UIViewController,UINavigationControllerDelegate, UIImagePickerControllerDelegate {
#IBOutlet var img:UIImageView!=nil
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning()
{
super.didReceiveMemoryWarning()
}
#IBAction func buttonTapped(AnyObject)
{
if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.PhotoLibrary){
println("Button capture")
var imag = UIImagePickerController()
imag.delegate = self
imag.sourceType = UIImagePickerControllerSourceType.PhotoLibrary;
//imag.mediaTypes = [kUTTypeImage];
imag.allowsEditing = false
self.presentViewController(imag, animated: true, completion: nil)
}
}
func imagePickerController(picker: UIImagePickerController!, didFinishPickingImage image: UIImage!, editingInfo: NSDictionary!) {
let selectedImage : UIImage = image
//var tempImage:UIImage = editingInfo[UIImagePickerControllerOriginalImage] as UIImage
img.image=selectedImage
self.dismissViewControllerAnimated(true, completion: nil)
}
}

Answer 4

Since swift 4.2 and xcode 10 the func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) change a bit.
at the function header the infoKey-Section changes from
didFinishPickingMediaWithInfo info: [String : Any] to
didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]
To get the originalImage you now have to call:
let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage or
let image = info[.originalImage] as? UIImage
find other infoKeys here (editedImage, imageURL and more...)

Answer 5

In Swift 5.2, iOS 14.2
class YourViewController: UIViewController,UINavigationControllerDelegate, UIImagePickerControllerDelegate {
#IBAction func btnTapped(_ sender: Any) {
let imagePickerController = UIImagePickerController()
imagePickerController.allowsEditing = false //If you want edit option set "true"
imagePickerController.sourceType = .photoLibrary
imagePickerController.delegate = self
present(imagePickerController, animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
let tempImage = info[UIImagePickerController.InfoKey.originalImage] as! UIImage
imgRoom.image = tempImage
self.dismiss(animated: true, completion: nil)
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
dismiss(animated: true, completion: nil)
}
}

Answer 6

Try this:
func imagePickerController(picker: UIImagePickerController!, didFinishPickingMediaWithInfo info:NSDictionary!) {
let tempImage = info[UIImagePickerControllerOriginalImage] as! UIImage
imagePreview.image = tempImage
or you can also use ? in place of !.