title: WPF ComboBox autocomplete from items
body: <p>I have a ComboBox where I load in every hour and minute constellation possible.
  This gives many items and to still keep this user friendly I want an autocomplete. But the thing is when I turn <code>IsEditable="true"</code> a user can also enter any value.</p>
  
  <pre><code>&lt;ComboBox x:Name="cmbStartZeit" IsTextSearchEnabled="True" /&gt;
  </code></pre>
  
  <p>I add the items in two for loops</p>
  
  <pre><code>for(int i = 00; i &lt;= 24; i++)
  {
      for(int j = 00; j &lt;= 59; j++)
      {
         cmbStartZeit.Items.Add(i.ToString("00") + ":" + j.ToString("00"));
      }
  }
  </code></pre>
  
  <p>How can I turn the autocomplete feature on without allowing the user to add custom values ?</p>