AzureFaceiOSDemo-ViewController::didSelectItemAt().swift

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    activityIndicator.startAnimating()

    let person = persons[indexPath.item]

    // Clear photos section
    self.photos = []
    collectionView.reloadSections([photosSection])

    // Disable interactions while finding similar images
    collectionView.isUserInteractionEnabled = false

    // Find photos that match the selected avatar
    AzureFaceRecognition.shared.findSimilars(faceId: person.faceId, faceIds: ContentManager.shared.allPhotosFaceIds) { (faceIds) in
        self.photos = ContentManager.shared.photos(withFaceIds: faceIds)
        self.collectionView.reloadSections([self.photosSection])
        self.collectionView.isUserInteractionEnabled = true

        self.activityIndicator.stopAnimating()
    }
}