private void DetachAdorners()
{
if (_myDropAdorner != null)
{
_myDropAdorner.Dispose();
_myDropAdorner = null;
}
if (_myDragAdorner != null)
{
_myDragAdorner.Dispose();
_myDragAdorner = null;
}
}
private void InitializeDropAdorner(ItemsControl itemsControl, DragEventArgs e)
{
if (_myDropAdorner != null)
{
return;
}
var adornerLayer = AdornerLayer.GetAdornerLayer(itemsControl);
var itemContainer = UIHelpers.GetItemContainerFromPointInItemsControl(itemsControl, e.GetPosition(itemsControl));
if (adornerLayer == null || itemContainer == null)
{
return;
}
var isPointInTopHalf = IsDropPointBeforeItem(itemsControl, e);
var isOrientationHorizontal = (DropIndication == Orientation.Horizontal);
_myDropAdorner = new DropAdorner(isPointInTopHalf, isOrientationHorizontal, itemContainer, adornerLayer);
}
private void _onDragEnter(object sender, DragEventArgs e) {
if (_isValidDropTarget(e)) {
var layer = AdornerLayer.GetAdornerLayer(this);
_dropAdorner = new DropAdorner(this, _getDragSourceBlock(e));
_dropAdorner.UpdateInsertionPoint(e);
layer.Add(_dropAdorner);
}
}