private void UpdateHelpers(object sender, DragEventArgs e)
{
DependencyObject HitObject = e.OriginalSource as DependencyObject;
//this.HandleAutoScroll(sender, e);
if (this.hitObject != HitObject)
{
this.hitObject = HitObject;
//Dispose old helper
this.DisposeHelpers();
//Get new list of helper
while (HitObject != null && HitObject != this.element)
{
if (HitObject is UIElement)
{
this.uiHelper.AddRange((from Helper in DragDrop.GetDragDropUiHelper(HitObject.GetType()) select Helper.Create((UIElement)HitObject)).ToArray());
}
HitObject = VisualTreeHelper.GetParent(HitObject);
}
}
}
/// <summary>
/// Gets the handler for the given UI element type used as drag and drop target
/// </summary>
/// <remarks>
/// <para>
/// The handlers are searched to find the most specific handler available for the type. This means,
/// first the handler for the exact type is searched for. If nothing is found, the search is repeated
/// with the base type and so on.
/// </para>
/// <para>
/// if nothing is foud, <c>null</c> is returned
/// </para>
/// </remarks>
public static IDragDropUiTargetHandler GetDragDropUITargetHandler(Type uiElementType)
{
return(DragDrop.GetDragDropUIHandler(DragDrop.dragTargetHandlers, uiElementType));
}
/// <summary>
/// Gets the handler for the given UI element type used as drag and drop target
/// </summary>
/// <remarks>
/// <para>
/// The handlers are searched to find the most specific handler available for the type. This means,
/// first the handler for the exact type is searched for. If nothing is found, the search is repeated
/// with the base type and so on.
/// </para>
/// <para>
/// if nothing is foud, <c>null</c> is returned
/// </para>
/// </remarks>
public static IDragDropUiSourceHandler GetDragDropUISourceHandler(Type uiElementType)
{
return(DragDrop.GetDragDropUIHandler(DragDrop.dragSourceHandlers, uiElementType));
}