XAML-Map-Control/MapControl/WPF/MapItem.WPF.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace MapControl
{
    public partial class MapItem
    {
        public static readonly DependencyProperty AutoCollapseProperty =
            DependencyPropertyHelper.AddOwner<MapItem, bool>(MapPanel.AutoCollapseProperty);

        public static readonly DependencyProperty LocationProperty =
            DependencyPropertyHelper.AddOwner<MapItem, Location>(MapPanel.LocationProperty, null,
                (item, oldValue, newValue) => item.UpdateMapTransform(newValue));

        static MapItem()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(MapItem), new FrameworkPropertyMetadata(typeof(MapItem)));
        }

        protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
        {
            if (Keyboard.Modifiers.HasFlag(ModifierKeys.Shift))
            {
                e.Handled = true;
                MapItemsControl.SelectItemsInRange(this);
            }
            else
            {
                base.OnMouseLeftButtonDown(e);
            }
        }
    }
}