public virtual void Drop(DropInfo dropInfo)
{
int insertIndex = dropInfo.InsertIndex;
IList destinationList = GetList(dropInfo.TargetCollection);
IEnumerable data = ExtractData(dropInfo.Data);
if (dropInfo.DragInfo.VisualSource == dropInfo.VisualTarget)
{
IList sourceList = GetList(dropInfo.DragInfo.SourceCollection);
foreach (object o in data)
{
int index = sourceList.IndexOf(o);
if (index != -1)
{
sourceList.RemoveAt(index);
if (sourceList == destinationList && index < insertIndex)
{
--insertIndex;
}
}
}
}
foreach (object o in data)
{
destinationList.Insert(insertIndex++, o);
}
}
public virtual void DragOver(DropInfo dropInfo)
{
if (CanAcceptData(dropInfo))
{
dropInfo.Effects = DragDropEffects.Copy;
dropInfo.DropTargetAdorner = DropTargetAdorners.Insert;
}
}
protected static bool CanAcceptData(DropInfo dropInfo)
{
if (dropInfo.DragInfo.SourceCollection == dropInfo.TargetCollection)
{
return GetList(dropInfo.TargetCollection) != null;
}
else if (dropInfo.DragInfo.SourceCollection is ItemCollection)
{
return false;
}
else
{
if (TestCompatibleTypes(dropInfo.TargetCollection, dropInfo.Data))
{
return !IsChildOf(dropInfo.VisualTargetItem, dropInfo.DragInfo.VisualSourceItem);
}
else
{
return false;
}
}
}
static void DropTarget_PreviewDrop(object sender, DragEventArgs e)
{
DropInfo dropInfo = new DropInfo(sender, e, m_DragInfo, m_Format.Name);
IDropTarget dropHandler = GetDropHandler((UIElement)sender);
DragAdorner = null;
DropTargetAdorner = null;
if (dropHandler != null)
{
dropHandler.Drop(dropInfo);
}
else
{
DefaultDropHandler.Drop(dropInfo);
}
e.Handled = true;
}
static void DropTarget_PreviewDragOver(object sender, DragEventArgs e)
{
DropInfo dropInfo = new DropInfo(sender, e, m_DragInfo, m_Format.Name);
IDropTarget dropHandler = GetDropHandler((UIElement)sender);
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 (sender is ItemsControl)
{
UIElement adornedElement = ((ItemsControl)sender).GetVisualDescendent<ItemsPresenter>();
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);
}