zoom entire UICollectionView

Question

I have an iPad App where I\'m using a UICollectionView and each UICollectionViewCell contains just a single UIImage. Currently I\'m displaying per 9 UIImages (3 rows * 3 col

Answer 1

For Xamarin.iOS developers I founded this solution: add a UIScrollView element to the main view and add the UICollectionView as an element of the UIScrollView. Then create a zoom delegate for the UIScrollView.

MainScrollView = new UIScrollView(new CGRect(View.Frame.X, View.Frame.Y, size.Width, size.Height));


        _cellReuseId = GenCellReuseId();

        _contentScroll = new UICollectionView(new CGRect(View.Frame.X, View.Frame.Y, size.Width, size.Height), new InfiniteScrollCollectionLayout(size.Width, size.Height));

        _contentScroll.AllowsSelection = true;
        _contentScroll.ReloadData();


        _contentScroll.Center = MainScrollView.Center;
        _contentScroll.Frame = new CGRect(_contentScroll.Frame.X, _contentScroll.Frame.Y - 32, _contentScroll.Frame.Width, _contentScroll.Frame.Height);
        MainScrollView.ContentSize = _contentScroll.ContentSize;
        MainScrollView.AddSubview(_contentScroll);
        MainScrollView.MaximumZoomScale = 4f;
        MainScrollView.MinimumZoomScale = 1f;
        MainScrollView.BouncesZoom = true;
        MainScrollView.ViewForZoomingInScrollView += (UIScrollView sv) =>
        {
            if (_contentScroll.Frame.Height < sv.Frame.Height && _contentScroll.Frame.Width < sv.Frame.Width)
            {
                _contentScroll.Center = MainScrollView.Center;
                _contentScroll.Frame = new CGRect(_contentScroll.Frame.X, _contentScroll.Frame.Y - 64, _contentScroll.Frame.Width, _contentScroll.Frame.Height);
                _contentScroll.BouncesZoom = true;
                _contentScroll.AlwaysBounceHorizontal = false;
            }
            return _contentScroll;
};