title: silverlight combobox invokecommandaction on selectionchanged event cannot pass parameter
body: <p>I have a combobox, using databinding and MVVM pattern. Everytime the user changes the selection, I added an event trigger, and a command is executed. the code is the following:</p>
  
  <pre><code> &lt;ComboBox x:Name="myComboBox" Width="150" ItemsSource="{Binding Items}" &gt;
                                  &lt;ComboBox.ItemTemplate&gt;
                                      &lt;DataTemplate&gt;
                                          &lt;StackPanel&gt;
                                              &lt;TextBlock Text="{Binding Name}"/&gt;
                                          &lt;/StackPanel&gt;
                                      &lt;/DataTemplate&gt;
                                  &lt;/ComboBox.ItemTemplate&gt;
                                  &lt;i:Interaction.Triggers&gt;
                                      &lt;i:EventTrigger EventName="SelectionChanged"&gt;
                                          &lt;i:InvokeCommandAction Command="{Binding LoadCommand}" CommandParameter="{Binding SelectedItem, ElementName=myComboBox}" /&gt;
                                      &lt;/i:EventTrigger&gt;
                                  &lt;/i:Interaction.Triggers&gt;
                              &lt;/ComboBox&gt;
  </code></pre>
  
  <p>the problem is that the parameter it passes is always null.</p>