private static void ItemsControl_PreviewMouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
if (sender is ItemsControl itemsControl)
{
DragStatusEnum dragStatus = GetDragStatus(itemsControl);
switch (dragStatus)
{
case DragStatusEnum.None:
break;
case DragStatusEnum.Begining:
{
if (e.LeftButton == System.Windows.Input.MouseButtonState.Pressed)
{
Vector vector = e.GetPosition(itemsControl) - mouseDownPoint;
if (vector.X > dragBeginedOffset || vector.Y > dragBeginedOffset)
{
SetDragStatus(itemsControl, DragStatusEnum.Draging);
if (dragInfo.ItemContainer is FrameworkElement frameworkElement)
{
frameworkElement.CaptureMouse();
if (dragAdorner != null)
{
dragAdorner.Detath();
}
Point offset = e.GetPosition(frameworkElement);
dragAdorner = new DragAdorner(itemsControl, frameworkElement, new Point()
{
X = -offset.X, Y = -offset.Y
});
}
}
}
}
break;
case DragStatusEnum.Draging:
{
if (e.LeftButton == System.Windows.Input.MouseButtonState.Pressed)
{
if (dragAdorner != null)
{
dragAdorner.UpdatePoint(e.GetPosition(itemsControl));
}
if (GetItem(itemsControl.ItemContainerGenerator, itemsControl.InputHitTest(e.GetPosition(itemsControl)), out DependencyObject itemContainer, out object item))
{
if (/*itemContainer != dragInfo.ItemContainer && */ itemContainer is FrameworkElement frameworkElement)
{
if (lineAdorner == null)
{
lineAdorner = new LineAdorner(itemsControl);
lineAdorner.UpdateBrush(GetDropTargetLineBrush(itemsControl), GetDropTargetLineThickness(itemsControl));
lineAdorner.UpdateTarget(e.MouseDevice, frameworkElement, GetItemPanelOrientation(itemsControl));
}
else
{
lineAdorner.UpdateTarget(e.MouseDevice, frameworkElement, GetItemPanelOrientation(itemsControl));
}
}
}
else
{
if (lineAdorner != null)
{
lineAdorner.ClearTarget();
}
}
e.Handled = true;
}
}
break;
