private void OnDragInitiated()
{
DragActivity = DragActivity.Starting;
NotifyDragActivityChanged();
if (DragActivity != DragActivity.Canceled)
{
DragActivity = DragActivity.Started;
NotifyDragActivityChanged();
}
}
/// <summary>
/// Cancels the drag operation.
/// </summary>
public virtual void CancelDrag()
{
DragActivity = DragActivity.Canceled;
}