Hello,
these are my 2 classes a Attachable Property SelectedItems:
code is from here: http://stackoverflow.com/questions/1297643/sync-selecteditems-in-a-muliselect-listbox-with-a-collection-in-viewmodel
The namespace TBM.Helper is for sure proper as it works for other classes too.
The namespace reference is also in the xaml file:
xmlns:Helper="clr_namespace:TBM.Helper"
But <ListBox Helper:SelectedItems.Items="{Binding SelectedItems}" ...
does not work because =
The property 'SelectedItems.Items' does not exist in XML namespace 'clr_namespace:TBM.Helper'.
The attachable property 'Items' was not found in type 'SelectedItems
What do I have to change ?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Controls;
using System.Collections;
using System.Windows;
namespace TBM.Helper
{
public static class SelectedItems : DependencyObject
{
private static readonly DependencyProperty SelectedItemsBehaviorProperty =
DependencyProperty.RegisterAttached(
"SelectedItemsBehavior",
typeof(SelectedItemsBehavior),
typeof(ListBox),
null);
public static readonly DependencyProperty ItemsProperty = DependencyProperty.RegisterAttached(
"Items",
typeof(IList),
typeof(SelectedItems),
new PropertyMetadata(null, ItemsPropertyChanged));
public static void SetItems(ListBox listBox, IList list) { listBox.SetValue(ItemsProperty, list); }
public static IList GetItems(ListBox listBox) { return listBox.GetValue(ItemsProperty) as IList; }
private static void ItemsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var target = d as ListBox;
if (target != null)
{
GetOrCreateBehavior(target, e.NewValue as IList);
}
}
private static SelectedItemsBehavior GetOrCreateBehavior(ListBox target, IList list)
{
var behavior = target.GetValue(SelectedItemsBehaviorProperty) as SelectedItemsBehavior;
if (behavior == null)
{
behavior = new SelectedItemsBehavior(target, list);
target.SetValue(SelectedItemsBehaviorProperty, behavior);
}
return behavior;
}
}
}
using System.Windows;
using System.Windows.Controls;
using System.Collections;
namespace TBM.Helper
{
public class SelectedItemsBehavior
{
private readonly ListBox _listBox;
private readonly IList _boundList;
public SelectedItemsBehavior(ListBox listBox, IList boundList)
{
_boundList = boundList;
_listBox = listBox;
SetSelectedItems();
_listBox.SelectionChanged += OnSelectionChanged;
_listBox.DataContextChanged += OnDataContextChanged;
}
private void SetSelectedItems()
{
_listBox.SelectedItems.Clear();
foreach (object item in _boundList)
{
// References in _boundList might not be the same as in _listBox.Items
int i = _listBox.Items.IndexOf(item);
if (i >= 0)
_listBox.SelectedItems.Add(_listBox.Items[i]);
}
}
private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
SetSelectedItems();
}
private void OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
_boundList.Clear();
foreach (var item in _listBox.SelectedItems)
_boundList.Add(item);
}
}
}
