static void DropTarget_PreviewDragOver(object sender, DragEventArgs e)
{
DropInfo dropInfo = new DropInfo(sender, e, m_DragInfo);
IDropTarget dropHandler = GetDropHandler((UIElement)sender);
ItemsControl itemsControl = sender as ItemsControl;
if (dropHandler != null)
{
dropHandler.DragOver(dropInfo);
}
else
{
DefaultDropHandler.DragOver(dropInfo);
}
// Update the drag adorner.
if (dropInfo.Effects != DragDropEffects.None)
{
if (DragAdorner == null && m_DragInfo != null)
{
CreateDragAdorner();
}
if (DragAdorner != null)
{
DragAdorner.MousePosition = e.GetPosition(DragAdorner.AdornedElement);
DragAdorner.InvalidateVisual();
}
}
else
{
DragAdorner = null;
}
// If the target is an ItemsControl then update the drop target adorner.
if (itemsControl != null)
{
// Display the adorner in the control's ItemsPresenter. If there is no
// ItemsPresenter provided by the style, try getting hold of a
// ScrollContentPresenter and using that.
UIElement adornedElement =
(UIElement)itemsControl.GetVisualDescendent<ItemsPresenter>() ??
(UIElement)itemsControl.GetVisualDescendent<ScrollContentPresenter>();
if (adornedElement != null)
{
if (dropInfo.DropTargetAdorner == null)
{
DropTargetAdorner = null;
}
else if (!dropInfo.DropTargetAdorner.IsInstanceOfType(DropTargetAdorner))
{
DropTargetAdorner = DropTargetAdorner.Create(dropInfo.DropTargetAdorner, adornedElement);
}
if (DropTargetAdorner != null)
{
DropTargetAdorner.DropInfo = dropInfo;
DropTargetAdorner.InvalidateVisual();
}
}
}
e.Effects = dropInfo.Effects;
e.Handled = true;
Scroll((DependencyObject)sender, e);
}
static void DropTarget_PreviewDrop(object sender, DragEventArgs e)
{
DropInfo dropInfo = new DropInfo(sender, e, m_DragInfo);
IDropTarget dropHandler = GetDropHandler((UIElement)sender) ?? DefaultDropHandler;
IDragSource dragHandler = GetDragHandler((UIElement)sender) ?? DefaultDragHandler;
DragAdorner = null;
DropTargetAdorner = null;
dropHandler.Drop(dropInfo);
dragHandler.Dropped(dropInfo);
dropHandler.DragLeave(dropInfo);
e.Handled = true;
}
static void DropTarget_PreviewDragLeave(object sender, DragEventArgs e)
{
DropInfo dropInfo = new DropInfo(sender, e, m_DragInfo);
IDropTarget dropHandler = GetDropHandler((UIElement)sender);
if (dropHandler != null)
{
dropHandler.DragLeave(dropInfo);
}
DragAdorner = null;
DropTargetAdorner = null;
}