         
         for i in 0..<numShow {
             let image = dataSource.photoColletionView?(self, imageAt: i)
+            images.append(image)
             if let image = image {
-                images.append(image)
                 if i == 0 {
                     isVertical = image.size.width < image.size.height
                 }

    var margin: CGFloat = 1
    var maxImage = 4
    var photoViews: [PhotoView] = []
    var images: [UIImage] = []
    
    weak open var dataSource: PhotoCollectionViewDataSource?
    weak open var delegate: PhotoCollectionViewDelegate?

        }
    }
    
    func image(at index: Int) -> UIImage? {
        guard index >= 0 && index < images.count else {
            return nil
        }
        return images[index]
    }
    
    func tapPhotoView(sender: UITapGestureRecognizer) {
        if let tag = sender.view?.tag {
