title: How do you handle a ComboBox SelectionChanged in MVVM? Selection changed events are not firing.
body: <h2>ComboBox1</h2>
  
  <pre><code>  &lt;ComboBox Grid.Column="1" Grid.Row="1" Height="23" HorizontalAlignment="Center" Margin="2,2,0,0" Name="comboBoxServer" VerticalAlignment="Top" Width="156" ItemsSource="{Binding Path=ServerNameList, Mode=OneWay}" SelectedIndex="0" SelectedItem="{Binding SelectedIndex}" SelectionChanged="comboBoxServer_SelectionChanged" Text="{Binding selectedServer, Mode=OneWayToSource,UpdateSourceTrigger=PropertyChanged}" &gt;
                  &lt;i:Interaction.Triggers&gt;
                      &lt;i:EventTrigger EventName="SelectionChanged"&gt;
                          &lt;i:InvokeCommandAction Command="{Binding serverCommand}" CommandParameter="{Binding ElementName=comboBoxServer, Path=SelectedValue}"/&gt;
                      &lt;/i:EventTrigger&gt;
                  &lt;/i:Interaction.Triggers&gt;
              &lt;/ComboBox&gt;
  </code></pre>
  
  <h2>ComboBox2</h2>
  
  <pre><code>            &lt;ComboBox Grid.Column="1" Grid.Row="2" Height="23" HorizontalAlignment="Center" Margin="2,2,0,0" Name="comboBoxDBName" VerticalAlignment="Top" Width="156" ItemsSource="{Binding Path=DBNameList, Mode=OneWay}" SelectedItem="{Binding serverSelected, Mode=TwoWay}" &gt;
  
              &lt;/ComboBox&gt;
  </code></pre>
  
  <blockquote>
    <p>I want that on selecting value in first combo box, Second combo box should populate according to first combo box selection.</p>
  </blockquote>