title: How would you know which element of an ItemsControl sends an event in MVVM?
body: <p>Let's say I currently have an ItemsControl whose DataTemplate is a bunch of buttons.  I'm wiring up these buttons' click events, but how am I to know which button was clicked?  Should I not use a ItemsControl?  </p>
  
  <p>I'm trying to have no code-behind, but being pragmatic may be necessary.  </p>
  
  <pre><code>&lt;ItemsControl&gt;
      &lt;ItemsControl.ItemTemplate&gt;
          &lt;DataTemplate&gt;
              &lt;Button Margin="10"&gt;
                  &lt;i:Interaction.Triggers&gt;
                      &lt;i:EventTrigger EventName="Click"&gt;
                          &lt;GalaSoft_MvvmLight_Command:EventToCommand Command="{Binding ItemsControlButtonClicked, Mode=OneWay}"/&gt;
                      &lt;/i:EventTrigger&gt;
                  &lt;/i:Interaction.Triggers&gt;
              &lt;/Button&gt;
          &lt;/DataTemplate&gt;
      &lt;/ItemsControl.ItemTemplate&gt;
  &lt;/ItemsControl&gt;
  </code></pre>