title: WPF ListViewItem item CheckBox. How to get all selected items?
body: <p>I have a this code:</p>
  
  <pre><code>&lt;ListView Height="238" 
            HorizontalAlignment="Left" 
            Name="listView1" 
            VerticalAlignment="Top" 
            Width="503"
            ItemsSource="{Binding}"
            IsSynchronizedWithCurrentItem="True"&gt;
    &lt;ListView.View&gt;
      &lt;GridView&gt;
        &lt;GridView.Columns&gt;
          &lt;GridViewColumn&gt;
            &lt;GridViewColumn.CellTemplate&gt;
              &lt;DataTemplate&gt;
                &lt;CheckBox Tag="{Binding ID}"/&gt;
              &lt;/DataTemplate&gt;
            &lt;/GridViewColumn.CellTemplate&gt;
          &lt;/GridViewColumn&gt;
          &lt;GridViewColumn DisplayMemberBinding="{Binding ID}" Header="ID" /&gt;
          &lt;GridViewColumn DisplayMemberBinding="{Binding Name}" Header="Name" /&gt;
        &lt;/GridView.Columns&gt;
      &lt;/GridView&gt;
    &lt;/ListView.View&gt;
  &lt;/ListView&gt;
  </code></pre>
  
  <p>That produce this window:</p>
  
  <p><img src="https://i.stack.imgur.com/hsvbt.jpg" alt="Window rendered by code"></p>
  
  <p>How do I know how many checkboxes are selected, and get the value <code>Tag</code> of each <code>CheckBox</code> that is selected?</p>