private void RefreshFluidWrapPanel()
        {
            count = 0;
            var items = new ObservableCollection<UIElement>();
            var maxCount = _random.Next(15, 20);
            for (var i = 0; i < maxCount; i++)
            {
                var brush = _brushes[_random.Next(_brushes.Length)];
                var factorWidth = UseRandomChildSize ? _random.Next(1, 3) : 1;
                var factorHeight = UseRandomChildSize ? _random.Next(1, 3) : 1;

                var ctrl = new FluidItemControl
                {
                    Width = factorWidth * panel.ItemWidth,
                    Height = factorHeight * panel.ItemHeight,
                    Fill = brush,
                    Data = (++count).ToString()
                };

                items.Add(ctrl);
            }

            panel.ItemsSource = items;
        }
        private async void OnAdd(object sender, RoutedEventArgs e)
        {
            var brush = _brushes[_random.Next(_brushes.Length)];
            //var factor = 1;
            var factorWidth = UseRandomChildSize ? _random.Next(1, 3) : 1;
            var factorHeight = UseRandomChildSize ? _random.Next(1, 3) : 1;

            var ctrl = new FluidItemControl
            {
                Width = factorWidth * panel.ItemWidth,
                Height = factorHeight * panel.ItemHeight,
                Fill = brush,
                Data = (++count).ToString()
            };

            await panel.AddChildAsync(ctrl);
        }