ios - 当用户允许使用照片时，我在 swift 3 中看不到任何东西

Question

我有照片库图像的 Collection View 但是第一次出现问题，用户允许使用照片 - 当应用程序第一次运行并且用户允许使用照片时，用户看不到任何图像并且应该关闭该 View Controller 并再次返回以查看图像

代码如下:

import UIKit
import Photos

class typeandtranslateViewController: UIViewController , UIImagePickerControllerDelegate , UINavigationControllerDelegate , UICollectionViewDelegate, UICollectionViewDataSource  , UITextFieldDelegate {


static var checkTextField = Bool()

@IBOutlet var backgroundimg: UIImageView!
@IBOutlet var frontimg: UIImageView!
@IBOutlet weak var typeView: UIView!

let arr_img = NSMutableArray()
let arr_selected = NSMutableArray()

@IBOutlet var collview: UICollectionView!


@IBOutlet weak var sefareshTitleTextField: UITextField!


@IBAction func caneraButton(_ sender: UIButton) {

    if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.camera) {
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerControllerSourceType.camera ;

        imagePicker.allowsEditing = false
        self.present(imagePicker,animated: true , completion: nil)
    }

    print("Camera!")


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

    let selectedImage = info[UIImagePickerControllerOriginalImage] as! UIImage

    UIImageWriteToSavedPhotosAlbum(selectedImage,self,nil,nil)

    dismiss(animated: true, completion: nil)

    print("save Image ")



}
@IBOutlet weak var viewCamera: UIView!
override func viewDidLoad() {
    super.viewDidLoad()



    print("Text Field Condition ")

    if sefareshTitleTextField!.text! == "" {

        typeandtranslateViewController.checkTextField = false


        print("sefaresh title is nill")
    } else if sefareshTitleTextField!.text! != "" {


        typeandtranslateViewController.checkTextField = true
        print("sefaresh title isnt nill")

    }

    self.sefareshTitleTextField.delegate = self


    collview?.allowsMultipleSelection = true

    let allPhotosOptions : PHFetchOptions = PHFetchOptions.init()
    allPhotosOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: true)]
    let allPhotosResult = PHAsset.fetchAssets(with: .image, options: allPhotosOptions)
    allPhotosResult.enumerateObjects({ (asset, idx, stop) in

        self.arr_img.add(asset)

    })


    self.typeView.layer.cornerRadius = self.typeView.frame.size.height/50
    self.typeView.layer.borderWidth = 1
    self.typeView.layer.borderColor = UIColor.clear.cgColor
    self.typeView.clipsToBounds = true


    self.viewCamera.layer.cornerRadius = 5
    self.viewCamera.layer.borderWidth = 1
    self.viewCamera.layer.borderColor = UIColor.clear.cgColor
    self.viewCamera.clipsToBounds = true


    self.tabBarController?.tabBar.isHidden = true
    self.navigationController?.isNavigationBarHidden = true


    let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.light)
    let blurView = UIVisualEffectView(effect: blurEffect)

    blurView.frame =  CGRect(x: self.backgroundimg.frame.origin.x, y: self.backgroundimg.frame.origin.y, width: self.backgroundimg.frame.size.width, height: self.backgroundimg.frame.size.height)

    blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

    self.backgroundimg.addSubview(blurView)

}

func getAssetThumbnail(asset: PHAsset, size: CGFloat) -> UIImage {
    let retinaScale = UIScreen.main.scale
    let retinaSquare = CGSize(width: size * retinaScale, height: size * retinaScale)//CGSizeMake(size * retinaScale, size * retinaScale)
    let cropSizeLength = min(asset.pixelWidth, asset.pixelHeight)
    let square = CGRect(x: 0, y: 0, width: cropSizeLength, height: cropSizeLength)//CGRectMake(0, 0, CGFloat(cropSizeLength), CGFloat(cropSizeLength))
    let cropRect = square.applying(CGAffineTransform(scaleX: 1.0/CGFloat(asset.pixelWidth), y: 1.0/CGFloat(asset.pixelHeight)))

    let manager = PHImageManager.default()
    let options = PHImageRequestOptions()
    var thumbnail = UIImage()

    options.isSynchronous = true
    options.deliveryMode = .highQualityFormat
    options.resizeMode = .exact
    options.normalizedCropRect = cropRect

    manager.requestImage(for: asset, targetSize: retinaSquare, contentMode: .aspectFit, options: options, resultHandler: {(result, info)->Void in
        thumbnail = result!
    })


    return thumbnail
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.


}

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    self.view.endEditing(true);

    if sefareshTitleTextField!.text == "" {

        typeandtranslateViewController.checkTextField = false


        print("sefaresh title is nill")
    } else if sefareshTitleTextField!.text! != "" {


        typeandtranslateViewController.checkTextField = true
        print("sefaresh title isnt nill")

    }



    return false;



}

func textFieldDidBeginEditing(_ textField: UITextField) {

        if sefareshTitleTextField!.text! == "" {

        typeandtranslateViewController.checkTextField = false


        print("sefaresh title is nill")
        } else if sefareshTitleTextField!.text! != "" {


        typeandtranslateViewController.checkTextField = true
        print("sefaresh title isnt nill")

        }

}



//MARK:
//MARK: Collectioview methods


func collectionView(_ collectionView: UICollectionView,
                    numberOfItemsInSection section: Int) -> Int {
    return arr_img.count
}
func collectionView(_ collectionView: UICollectionView,
                    cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "celll",
                                                  for: indexPath)
    let imgview : UIImageView = cell.viewWithTag(20) as! UIImageView
    imgview.image = self.getAssetThumbnail(asset: self.arr_img.object(at: indexPath.row) as! PHAsset, size: 150)

    let selectView : UIImageView = cell.viewWithTag(22) as! UIImageView
    if arr_selected.contains(indexPath.row){

        selectView.image = UIImage(named: "Select.png")
    }else{

        selectView.image = UIImage(named: "radioCircleButton.png")

    }

    cell.layer.cornerRadius = 5
    cell.layer.borderWidth = 1
    cell.layer.borderColor = UIColor.clear.cgColor
    cell.clipsToBounds = true


    return cell
}

var selectedIndexes = [NSIndexPath]() {
    didSet {
        collview.reloadData()
    }
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
{



    if arr_selected.contains(indexPath.row){
        arr_selected.remove(indexPath.row)
    }else{
        arr_selected.add(indexPath.row)
    }

    self.collview.reloadData()

}



override func viewDidAppear(_ animated: Bool) {

    let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.dark)
    let blurView = UIVisualEffectView(effect: blurEffect)
    blurView.frame = backgroundimg.bounds
    backgroundimg.addSubview(blurView)
    backgroundimg.frame = self.view.bounds
}

@IBAction func backToTheMainCustom(_ sender: UIButton) {

    performSegue(withIdentifier: "backToTheMainCustom", sender: self)

    sefareshTitleTextField!.text! = ""

    typeandtranslateViewController.checkTextField = false
}

}

Answer 1

首先，您需要请求用户授予访问照片库的权限。如果请求是第一次发生，等待他的回答并再次打开 UIImagePickerController。请查看以下代码:

let photosAccess = PHPhotoLibrary.authorizationStatus()
switch photosAccess {
case .notDetermined:
    // First time here. Request the access
    PHPhotoLibrary.requestAuthorization({status in
        if status == .authorized{
            // Access was just granted
            // Open library here
        }
    })

case .authorized:
    // Open library here

case .denied, .restricted:
    // Photos access is not granted.
    // Good place to take user to app settings.
}

相机也一样:

AVCaptureDevice.requestAccess(forMediaType: AVMediaTypeVideo) { response in
    if response {
        DispatchQueue.main.async {
            // Show camera UI here
        }
    } else {
        DispatchQueue.main.async {
            // Access is restricred
        }
    }
}