public object ContainerFromItem(object item)
{
if (RowsListView.ItemsSource is ImageWallRows <Post> rows)
{
foreach (var row in rows)
{
if (RowsListView.ContainerFromItem(row) != null)
{
var container = RowsListView.ContainerFromItem(row) as ListViewItem;
if (container != null)
{
var root = (FrameworkElement)container.ContentTemplateRoot;
var innerListView = (ListView)root.FindName("InnerListView");
var c = innerListView.ContainerFromItem(item);
if (c != null)
{
return(c);
}
}
}
}
}
return(null);
}
private int getListViewCurrentRowIndex()
{
var listViewY = getElementPositionY(RowsListView);
var minOffset = double.MaxValue;
int minOffsetPageIndex = -1;
// Return -1 if there is no content loaded in the listview
if (RowsListView.Items.Count == 0)
{
return(-1);
}
for (int i = 0; i < RowsListView.Items.Count(); i++)
{
var container = RowsListView.ContainerFromIndex(i);
if (container != null)
{
if (((FrameworkElement)container).ActualHeight != 0)
{
var y = getElementPositionY((UIElement)container) - listViewY;
if (y != -listViewY)
{
// If the item is virtualized, its position Y will be 0
if (Math.Abs(y) <= minOffset)
{
minOffset = Math.Abs(y);
minOffsetPageIndex = i;
}
}
}
}
else
{
// This container is virtualized, Do nothing
}
}
return(minOffsetPageIndex);
}
private async void RowsListView_SizeChanged(object sender, SizeChangedEventArgs e)
{
if (this.DataContext == null)
{
return;
}
if ((RowsListView.ItemsSource as IImageWallRows) != null)
{
if (!resizePending && e.NewSize.Width - this.Padding.Left - this.Padding.Right == (RowsListView.ItemsSource as IImageWallRows).RowWidth)
{
return;
}
if (resizePending)
{
resizePending = false;
var temp = e.NewSize;
await Task.Delay(500);
if (RowsListView.RenderSize.Width == temp.Width)
{
var currentRow = getListViewCurrentRowIndex();
int currentRowMidItemIndex = 0;
if (currentRow != -1)
{
var t = (RowsListView.ItemsSource as IImageWallRows).t;
currentRowMidItemIndex = (RowsListView.ItemsSource as IEnumerable <object>).Take(currentRow).Sum(o => (o as IEnumerable <object>).Count());
currentRowMidItemIndex += ((dynamic)RowsListView.ItemsSource)[currentRow].Count / 2;
}
(RowsListView.ItemsSource as IImageWallRows).RowWidth = RowsListView.ActualWidth - RowsListView.Padding.Left - RowsListView.Padding.Right;
(RowsListView.ItemsSource as IImageWallRows).RowHeight = RowsListView.ActualWidth > 500 ? 300 : 150;
(RowsListView.ItemsSource as IImageWallRows).Resize();
if (currentRow != -1)
{
int sum = 0;
foreach (var row in (RowsListView.ItemsSource as IEnumerable <object>))
{
sum += (row as IEnumerable <object>).Count();
if (sum >= currentRowMidItemIndex)
{
RowsListView.ScrollIntoView(row, ScrollIntoViewAlignment.Leading);
break;
}
}
}
}
}
else
{
var temp = e.NewSize;
await Task.Delay(500);
if (RowsListView.RenderSize.Width == temp.Width)
{
var currentRow = getListViewCurrentRowIndex();
int currentRowMidItemIndex = 0;
if (currentRow != -1)
{
var t = (RowsListView.ItemsSource as IImageWallRows).t;
currentRowMidItemIndex = (RowsListView.ItemsSource as IEnumerable <object>).Take(currentRow).Sum(o => (o as IEnumerable <object>).Count());
if (currentRow + 1 <= (RowsListView.ItemsSource as IList).Count)
{
var next = (RowsListView.ItemsSource as IEnumerable <object>).Take(currentRow + 1).Sum(o => (o as IEnumerable <object>).Count());
currentRowMidItemIndex = (currentRowMidItemIndex + next) / 2;
}
}
(RowsListView.ItemsSource as IImageWallRows).RowWidth = RowsListView.ActualWidth - RowsListView.Padding.Left - RowsListView.Padding.Right;
(RowsListView.ItemsSource as IImageWallRows).RowHeight = RowsListView.ActualWidth > 500 ? 300 : 150;
(RowsListView.ItemsSource as IImageWallRows).Resize();
if (currentRow != -1)
{
int sum = 0;
foreach (var row in (RowsListView.ItemsSource as IEnumerable <object>))
{
sum += (row as IEnumerable <object>).Count();
if (sum >= currentRowMidItemIndex)
{
RowsListView.ScrollIntoView(row, ScrollIntoViewAlignment.Leading);
break;
}
}
}
}
}
}
}