Wpf – Multiselect ListBox

Bind IsSelected to a property in your data class. When the property is changed, execute the logic to update the IsSelected property in other data objects:

<ListBox>
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="IsSelected" Value="{Binding IsSelected}"/>
        </Style>
    </ListBox.ItemContainerStyle>
</ListBox>

Then in your data class you can have something like this:

public bool IsSelected
{
    get { return _isSelected; }
    set
    {
        if (_isSelected != value)
        {
            _isSelected = value;
            OnPropertyChanged("IsSelected");

            UpdateOtherItems();
        }
    }
}

Or you could have the data item raise an IsSelectedChanged event and have the owning class manage the interdependencies of the selection.

i dont know mvvm way of doing this, i have a working solution comibined of mvvm & codebehind.

CodeBehind

private void lstbox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)
    {
        var listBox = sender as ListBox;
        if (listBox == null) return;

        var viewModel = listBox.DataContext as Window1ViewModel;
        if (viewModel == null) return;

        viewModel.ListOfSelectedItems.Clear();

        foreach (Window1ViewModel.States item in listBox.SelectedItems)
        {
            viewModel.ListOfSelectedItems.Add(item);
        }
      }

ViewModel

    private ObservableCollection<States> _listofselecteditems;
    public ObservableCollection<States> ListOfSelectedItems
    {
        get
        {
            return _listofselecteditems;
        }
        set
        {
            _listofselecteditems = value;
            RaisePropertyChanged(() => ListOfSelectedItems);
        }
    }

Xaml

            <ListBox x:Name="lstbox" 
             SelectionChanged="lstbox_SelectionChanged_1"
             ItemsSource="{Binding StatesList,Mode=TwoWay}"
             SelectionMode="Multiple" >
        <ListBox.ItemTemplate>
            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <CheckBox 
                        IsChecked="{Binding Path=IsSelected,Mode=TwoWay}"
                        Content="{Binding StateName}" />
                    <TextBox Margin="8,0,0,0" Text="{Binding SOmeProperty}" IsEnabled="{Binding Path=IsSelected}"/>
                </StackPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>