title: ListBox CheckBox IsChecked binding using MVVM
body: <p>I'm trying to figure out a way to bind my <code>CheckBox</code> <code>IsChecked</code> property.  Basically, I have a list of items which the <code>ListBox</code> is bound to.  When a user checks the box, a command is invoked and that item is added to a collection.</p>
  
  <p>However, what if I want to programmatically select items in the list?  I would like the <code>IsChecked</code> item to be based on whether or not the item exists in a list in the ViewModel.</p>
  
  <p>In other words, if in my viewmodel, I do something like <code>vm.MySelectedItems.Add(thisItem)</code>, I would like the <code>CheckBox</code> to be <code>Checked</code>.</p>
  
  <p>Is this possible and if so, how should I go about it?</p>
  
  <p>Thank you.</p>
  
  <pre><code>&lt;ListBox.ItemTemplate&gt;
      &lt;DataTemplate&gt;
          &lt;WrapPanel&gt;
              &lt;CheckBox IsChecked={Binding ???} /&gt;
              &lt;TextBlock VerticalAlignment="Center" Text="{Binding Converter={StaticResource nameConverter}}" /&gt;
          &lt;/WrapPanel&gt;
      &lt;/DataTemplate&gt;
  &lt;/ListBox.ItemTemplate&gt;
  </code></pre>