public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new MainWindowViewModel();
        }
    }

<ListBox ItemsSource="{Binding Items}" SelectionMode="Multiple" >
    <ListBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding DisplayText}" />
        </DataTemplate>
    </ListBox.ItemTemplate>
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="IsSelected"
                    Value="{Binding IsSelected}" />
        </Style>
    </ListBox.ItemContainerStyle>
</ListBox>

public partial class MainWindowViewModel : ObservableObject
{
    private List<SelectableItem> _items;
    public List<SelectableItem> Items
    {
        get => _items;
        set
        {
            _items = value;
            OnPropertyChanged(nameof(Items));
        }
    }

    public MainWindowViewModel()
    {
        _items = new List<SelectableItem>
        {
            new SelectableItem { DisplayText = "Entry01"},
            new SelectableItem { DisplayText = "Entry02"},
            new SelectableItem { DisplayText = "Entry03"},
            new SelectableItem { DisplayText = "Entry04"},
        };
    }
}

public class SelectableItem : ObservableObject
{
    private string _displayText;
    public string DisplayText
    {
        get => _displayText;
        set
        {
            _displayText = value;
            OnPropertyChanged(nameof(_displayText));
        }
    }

    private bool _isSelected;
    public bool IsSelected
    {
        get => _isSelected;
        set
        {
            _isSelected = value;
            OnPropertyChanged(nameof(_isSelected));
        }
    }
}