MARKUS

using System;

using System.Collections;

using System.Collections.Generic;

using System.Collections.Specialized;

using System.Windows;

using System.Windows.Interactivity;

using Telerik.Windows.Controls;

namespace Markus.Service.StationController.Controls

{

    class GridViewSelectionUtilities : Behavior<RadGridView>

    {

        private RadGridView Grid

        {

            get

            {

                return AssociatedObject as RadGridView;

            }

        }

        public INotifyCollectionChanged SelectedItems

        {

            get { return (INotifyCollectionChanged)GetValue(SelectedItemsProperty); }

            set { SetValue(SelectedItemsProperty, value); }

        }

        // Using a DependencyProperty as the backing store for SelectedItemsProperty.  This enables animation, styling, binding, etc...

        public static readonly DependencyProperty SelectedItemsProperty =

            DependencyProperty.Register("SelectedItems", typeof(INotifyCollectionChanged), typeof(GridViewSelectionUtilities), new PropertyMetadata(OnSelectedItemsPropertyChanged));

        private static void OnSelectedItemsPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)

        {

            var collection = args.NewValue as INotifyCollectionChanged;

            if (collection != null)

            {

                collection.CollectionChanged += ((GridViewSelectionUtilities)target).ContextSelectedItems_CollectionChanged;

            }

        }

        protected override void OnAttached()

        {

            base.OnAttached();

            Grid.SelectedItems.CollectionChanged += GridSelectedItems_CollectionChanged;

        }

        void ContextSelectedItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)

        {

            UnsubscribeFromEvents();

            Transfer(SelectedItems as IList, Grid.SelectedItems);

            SubscribeToEvents();

        }

        void GridSelectedItems_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)

        {

            UnsubscribeFromEvents();

            Transfer(Grid.SelectedItems, SelectedItems as IList);

            SubscribeToEvents();

        }

        private void SubscribeToEvents()

        {

            Grid.SelectedItems.CollectionChanged += GridSelectedItems_CollectionChanged;

            if (SelectedItems != null)

            {

                SelectedItems.CollectionChanged += ContextSelectedItems_CollectionChanged;

            }

        }

        private void UnsubscribeFromEvents()

        {

            Grid.SelectedItems.CollectionChanged -= GridSelectedItems_CollectionChanged;

            if (SelectedItems != null)

            {

                SelectedItems.CollectionChanged -= ContextSelectedItems_CollectionChanged;

            }

        }

        public static void Transfer(IList source, IList target)

        {

            if (source == null || target == null)

                return;

            target.Clear();

            foreach (var o in source)

            {

                target.Add(o);

            }

        }

    }

}