<ListView x:Name="listview" Background="Azure" SelectionMode="Multiple"
         ItemsSource="{Binding Strings}" RenderTransformOrigin="0.5,0.5" Width="343">
            <ListView.ItemTemplate>
                <DataTemplate x:Name="datatemplate">
                    <CheckBox x:Name="CheckBoxZone" IsChecked="{Binding RelativeSource={RelativeSource AncestorType=ListViewItem},Path=IsSelected}"
                              Content="{Binding que_text}" Margin="0,5,0,0"/>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
        <Button  Style="{StaticResource ResourceKey=button_style }" x:Name="addToSurvey" Content="Add" Click="AddToSurvey_Click" />

private void AddToSurvey_Click(object sender, RoutedEventArgs e)
        {

            //foreach (var item in listview.SelectedItems)
            for (int i=0;i< listview.SelectedItems.Count;i++)
            {
                string que = listview.Items[i].ToString(); //did not work

            }

        }

public class Questions
    {
        public int que_id { get; set; }
        public string que_text { get; set; }
    }