title: Cannot get a selected text or value in ComboBox
body: <p>I have a combox in my wpf application with three items:</p>
  
  <pre><code>&lt;ComboBoxItem Tag="some value"&gt;Text&lt;/ComboBoxItem&gt;
  &lt;ComboBoxItem Tag="some value2"&gt;Text2&lt;/ComboBoxItem&gt;
  &lt;ComboBoxItem Tag="some value3"&gt;Text3&lt;/ComboBoxItem&gt;
  </code></pre>
  
  <p>I want to get a selected text or value at runtime. When I do this:</p>
  
  <pre><code>myComboBox.SelectedValue.ToString()
  </code></pre>
  
  <p>it returns this:</p>
  
  <pre><code>System.Windows.Controls.ComboBoxItem: Text2
  </code></pre>
  
  <p>How can I get a selected text or value?</p>