访问和使用IOS相机

Question

我正在尝试学习如何在IOS设备上访问和使用相机，我真的无法找到它上面的所有信息，至少不是那些最新或有用的初学者级别。

无论如何，我已经尝试了下面的代码但没有任何反应当我点击按钮打开相机它只是冻结并且什么都不做，我错过了什么或者我做错了什么？

import UIKit
import MobileCoreServices

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    @IBOutlet weak var myImg: UIImageView!
    var newMedia: Bool!

    @IBAction func cameraRoll(_ sender: Any) {
        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.savedPhotosAlbum){
            let imagePicker = UIImagePickerController()

            imagePicker.delegate = self
            imagePicker.sourceType = UIImagePickerControllerSourceType.photoLibrary
            imagePicker.mediaTypes = [kUTTypeImage as String]
            imagePicker.allowsEditing = false
            self.present(imagePicker, animated: true, completion: nil)
            newMedia = false
        }
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        let mediaType = info[UIImagePickerControllerMediaType] as! NSString

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

        if mediaType.isEqual(to: kUTTypeImage as String){
            let image = info[UIImagePickerControllerOriginalImage] as! UIImage

            myImg.image = image

            if (newMedia == true) {
                UIImageWriteToSavedPhotosAlbum(image, self, #selector(ViewController.image(image:didFinishsavingWithError:contextInfo:)), nil)

            } else if mediaType.isEqual(to: kUTTypeMovie as String){
                //vid support
            }
        }
    }

    func image(image: UIImage, didFinishsavingWithError error: NSErrorPointer, contextInfo:UnsafeRawPointer){
        if error != nil {
            let alert = UIAlertController(title: "Save Failed", message: "Failed to save image", preferredStyle: UIAlertControllerStyle.alert)

            let cancelAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
            alert.addAction(cancelAction)
            self.present(alert, animated: true, completion: nil)
        }
    }

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

    @IBAction func takePhoto(_ sender: Any) {

        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.camera){

            let imagePicker = UIImagePickerController()

            imagePicker.delegate = self
            imagePicker.sourceType = UIImagePickerControllerSourceType.photoLibrary
            imagePicker.mediaTypes = [kUTTypeImage as String]
            imagePicker.allowsEditing = false
            self.present(imagePicker, animated: true, completion:  nil)
            newMedia = false
        }     
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }
}