如何从swift 3.1中的照片库获取照片信息

Question

万圣节可以有人帮助我吗？ 如何知道从照片库中拍摄的照片模式。

import UIKit
import Photos

class ViewController: UIViewController,UITextFieldDelegate, UIImagePickerControllerDelegate,UINavigationControllerDelegate {

lazy var mealTxtField: paddingTextField = {
    let txt = paddingTextField()
    txt.placeholder = "Enter meal name"
    txt.layer.borderColor = UIColor.orange.cgColor
    txt.layer.borderWidth = 1
    txt.delegate = self
    return txt
}()
var mealNameLbl: UILabel = {
    let lbl = UILabel()
    lbl.text = "Meal name : "
    return lbl
}()
var setLabelBtn:UIButton = {
    let btn = UIButton(type: .system)
    btn.setTitle("Set defaul lable text", for: .normal)
    btn.addTarget(self, action: #selector(setLabel), for: .touchUpInside)
    return btn
}()
var mealImage: UIImageView = {
    let img = UIImageView()
    img.image = UIImage(named: "seafood01")
    img.contentMode = .scaleToFill
    return img
}()
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    view.addSubview(mealNameLbl)
    view.addSubview(mealTxtField)
    view.addSubview(setLabelBtn)
    view.addSubview(mealImage)

    //set layout 
    _ = mealNameLbl.anchor(view.topAnchor, left: view.leftAnchor, bottom: nil, right: nil, topConstant: 64, leftConstant: 20, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 30)
    _ = mealTxtField.anchor(mealNameLbl.bottomAnchor, left: view.leftAnchor, bottom: nil, right: view.rightAnchor, topConstant: 8, leftConstant: 20, bottomConstant: 0, rightConstant: 20, widthConstant: 0, heightConstant: 30)
    _ = setLabelBtn.anchor(mealTxtField.bottomAnchor, left: view.leftAnchor, bottom: nil, right: nil, topConstant: 8, leftConstant: 20, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 30)
    _ = mealImage.anchor(setLabelBtn.bottomAnchor, left: view.leftAnchor, bottom: nil, right: view.rightAnchor, topConstant: 8, leftConstant: 20, bottomConstant: 20, rightConstant: 20, widthConstant: 0, heightConstant: 0)

    // some other code 
    let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(selectImageFromPhotoLibrary(_:)))
    mealImage.isUserInteractionEnabled = true
    mealImage.addGestureRecognizer(tapGestureRecognizer)
}
func setLabel()  {
   mealNameLbl.text = "Set to defaul label"
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return true
}
func textFieldDidEndEditing(_ textField: UITextField) {
    mealNameLbl.text = textField.text
}
func selectImageFromPhotoLibrary(_ sender: UITapGestureRecognizer) {
    mealTxtField.resignFirstResponder()
    // UIImagePickerController is a view controller that lets a user pick media from their photo library.
    let imagePickerController = UIImagePickerController()
    // Only allow photos to be picked, not taken.
    imagePickerController.sourceType = .photoLibrary

    // Make sure ViewController is notified when the user picks an image.
    imagePickerController.delegate = self
    present(imagePickerController, animated: true, completion: nil)
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    dismiss(animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }
    mealImage.image = selectedImage
    dismiss(animated: true, completion: nil)
}