private void OnDragOver(object sender, DragEventArgs e)
{
//Debug.WriteLine("OnDragOver. IsReordering: {0}", isReordering);
if (!isReordering || draggingItemIndex_original == -1)
{
return;
}
e.Handled = true;
//Get the list of items under the current position
var position = e.GetPosition(null);
var hitContainer = VisualTreeHelper
.FindElementsInHostCoordinates(position, this, false)
.OfType <SelectorItem>()
.Where(x => x != Children[draggingItemIndex_original])
.FirstOrDefault();
int newDropAtIndex = (hitContainer == null)
? -1
: ParentListView.IndexFromContainer(hitContainer);//elements.IndexOf(hitContainers[0]);
if (newDropAtIndex == draggingItemIndex_original)
{
return;
}
//prevent mess: disable reorder on same position (prevent infinite reordering)
if (lastDragOverPosition != null)
{
hitContainer = VisualTreeHelper
.FindElementsInHostCoordinates((Point)lastDragOverPosition, this, false)
.OfType <SelectorItem>()
.Where(x => x != Children[draggingItemIndex_original])
.FirstOrDefault();
var index = (hitContainer == null)
? -1
: ParentListView.IndexFromContainer(hitContainer);
if (index == newDropAtIndex)
{
return;
}
lastDragOverPosition = null;
}
if (newDropAtIndex < 0)
{
return;
}
lastDragOverPosition = position;
dropAtIndex_elements = elements.IndexOf(Children[newDropAtIndex]);
//Debug.WriteLine("OnDragOver. Drag: {0}, Drop: {1}, OldDrop: {2}", draggingItemIndex_original, dropAtIndex_elements, dropAtIndex_original);
dropAtIndex_original = newDropAtIndex;
#if WINDOWS_UWP
e.AcceptedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.Move;
#endif
InvalidateMeasure();
}
