Why My Collection View Doesn't show my camera roll? - swift3

Question

I have a collection view that should shows camera roll photos But It didn't show any thing!
I saw similar questions But Their code didn't work !
I added privacy for using album photos in Info.plist
here is my code
class ViewController: UICollectionViewController , UICollectionViewDelegateFlowLayout {
override func viewDidLoad() {
grabPhotos()
}
func grabPhotos() {
var imageArray = [UIImage]()
let imgManager = PHImageManager.default()
let requestOptions = PHImageRequestOptions()
requestOptions.isSynchronous = true
requestOptions.deliveryMode = .highQualityFormat
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: true)]
if let fetchResult: PHFetchResult = PHAsset.fetchAssets(with: PHAssetMediaType.image, options: fetchOptions) {
if fetchResult.count > 0 {
for i in 0..<fetchResult.count {
imgManager.requestImage(for: fetchResult.object(at: i) , targetSize: CGSize(width: 200, height: 200), contentMode: .aspectFill, options: requestOptions, resultHandler: {
image , error in
imageArray.append(image!)
})
}
}
else {
print("No Photos")
self.collectionView?.reloadData()
}
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return imageArray.count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath as IndexPath)
let imageView = cell.viewWithTag(1) as! UIImageView
imageView.image = imageArray[indexPath.row]
return cell
}
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout:
UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
let width = collectionView.frame.width / 3 - 1
return CGSize(width: width, height: width)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 1.0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 1.0
}
}
It Shows Nothing I read Similar questions But they didn't help me