title: How to make simple combobox with selected value in XAML?
body: <p>What is the correct syntax to select a combobox item with <em>value</em> (not index) in pure XAML?</p>
  
  <p><strong>Doesn't work:</strong></p>
  
  <pre><code>&lt;StackPanel&gt;
      &lt;ComboBox SelectedValue="CA"&gt;
          &lt;ComboBoxItem Tag="CO"&gt;Colorado&lt;/ComboBoxItem&gt;
          &lt;ComboBoxItem Tag="CA"&gt;California&lt;/ComboBoxItem&gt;
          &lt;ComboBoxItem Tag="NM"&gt;New Mexico&lt;/ComboBoxItem&gt;
      &lt;/ComboBox&gt;
  &lt;/StackPanel&gt;
  </code></pre>
  
  <p><strong>Doesn't work:</strong></p>
  
  <pre><code>&lt;StackPanel&gt;
      &lt;ComboBox SelectedValue="CA"&gt;
          &lt;ComboBoxItem Value="CO"&gt;Colorado&lt;/ComboBoxItem&gt;
          &lt;ComboBoxItem Value="CA"&gt;California&lt;/ComboBoxItem&gt;
          &lt;ComboBoxItem Value="NM"&gt;New Mexico&lt;/ComboBoxItem&gt;
      &lt;/ComboBox&gt;
  &lt;/StackPanel&gt;
  </code></pre>
  
  <p><strong>Even this doesn't work:</strong></p>
  
  <pre><code>&lt;ComboBox SelectedValue="Colorado"&gt;
      &lt;ComboBoxItem Tag="CO"&gt;Colorado&lt;/ComboBoxItem&gt;
      &lt;ComboBoxItem Tag="CA"&gt;California&lt;/ComboBoxItem&gt;
      &lt;ComboBoxItem Tag="NM"&gt;New Mexico&lt;/ComboBoxItem&gt;
  &lt;/ComboBox&gt;
  </code></pre>
  
  <p><strong>This doesn't work:</strong></p>
  
  <pre><code>&lt;StackPanel&gt;
      &lt;ComboBox SelectedItem="CA"&gt;
          &lt;ComboBoxItem Tag="CO"&gt;Colorado&lt;/ComboBoxItem&gt;
          &lt;ComboBoxItem Tag="CA"&gt;California&lt;/ComboBoxItem&gt;
          &lt;ComboBoxItem Tag="NM"&gt;New Mexico&lt;/ComboBoxItem&gt;
      &lt;/ComboBox&gt;
  &lt;/StackPanel&gt;
  </code></pre>