CheckComboBox Help

The report names the CheckComboBox XAML and the CirculationData and ComboCirculation01_ItemSelectionChanged entry points, but no repository files or tests. Start by reproducing the three reported selection cases with the XML-backed ItemsSource; the work is complete when each case has a confirmed outcome and the expected selected values are clear.

HI,
I'm trying to use the CheckComboBox control, I take the data from an XML file, which is present in a folder on the computer, to be exact "C:\Emergency\Configuration\Configuration.xml" I used xmlDocument to import the file , and then through a foreach I added the various items, but I have two problems.

1. If I select only one item it is not shown
2. If I select two elements they are shown, but if I deselect them, the last deselected element is also shown
3. Question: How can I get the values pressed on 2 or more different strings?

Thank you so much :)

XAML CODE

<xctk:CheckComboBox Grid.Column="1" Grid.Row="4" x:Name="ComboCirculation01" Height="30" Width="200" HorizontalAlignment="Center" VerticalAlignment="Center" DisplayMemberPath="Color" ValueMemberPath="Level" SelectedValue="{Binding SelectedValue}" SelectedItemsOverride="{Binding SelectedItems}"/>

CS CODE

` #region Circulation

    public class CirculationItem {
        public string Circulation { get; set; }
        public bool IsSelected { get; set; }
    }

    private void CirculationData() {
        string configFile = @"C:\Emergenza\Configuration\Configuration.xml";

        XmlDocument xmlDocument = new XmlDocument();
        xmlDocument.Load(configFile);

        XmlNodeList nodes = xmlDocument.SelectNodes("/Config/Paziente/Associazione/Circolo/Value");

        ComboCirculation01.DisplayMemberPath = "Circulation"; 

        List<CirculationItem> circulationItems = new List<CirculationItem>();
         
        foreach (XmlNode node in nodes) {
            string circulation = node.InnerText;
            circulationItems.Add(new CirculationItem { Circulation = circulation });
        }

        ComboCirculation01.ItemsSource = circulationItems;
        ComboCirculation01.ItemSelectionChanged += ComboCirculation01_ItemSelectionChanged;
    }

    private void ComboCirculation01_ItemSelectionChanged(object sender, Xceed.Wpf.Toolkit.Primitives.ItemSelectionChangedEventArgs e) {
        foreach (CirculationItem item in ComboCirculation01.Items) {
            item.IsSelected = ComboCirculation01.SelectedItems.Contains(item);
        }
    }

    #endregion`

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