title: SelectionChanged event binding in Silverlight+MVVM-Light
body: <p>The handler of the "SelectionChanged" event of the ComboBox control has the following signature:</p>
  
  <pre><code>void SelectionChangedMethod(object sender, SelectionChangedEventArgs e)
  </code></pre>
  
  <p>How to bind to that property under Silverlight 4 and MVVM-Light to the corresponding method of the ViewModel object?</p>
  
  <p>As far as I know, I need to do something like this:</p>
  
  <pre><code>public void Changed(Object obj, SelectionChangedEventArgs e)
  {
      // .... implement logic here
  }
  
  RelayCommand&lt;Object, SelectionChangedEventArgs&gt; _command;
  public ICommand ObjectSelectionChanged
  {
      get
      {
          if (_command == null)
          {
              _command = new RelayCommand&lt;Object, SelectionChangedEventArgs&gt;(Changed);
          }
          return _command;
      }
  }
  </code></pre>
  
  <p>The problem is that RelayCommand class in the MVVM-Light framework doesn't support 2 generic parameters...</p>
  
  <p>Is there any solution or workaround for this case? How bind control event to the method with 2 parameters?</p>
  
  <p>And another problem: ComboBox doesn't have "Command" property to bind this command..? How can I get event to the ViewModel?</p>
  
  <p>Thanks.</p>
  
  <p>P.S. I've tried to use SelectedItem property of the combobox, but it seems like ComboBox implementation is not correct and it doesn't work...</p>