title: Binding CalendarView DateChange event with MvvmCross
body: <p>I have a CalendarView that looks like this:</p>
  
  <pre><code>&lt;CalendarView
    android:layout_width="match_parent"
    android:layout_height="300dp"
    android:id="@+id/createReservationCalendarView" /&gt;
  </code></pre>
  
  <p>Here is how I handle the DateChange event without MvvmCross:</p>
  
  <pre><code>protected override void OnCreate(Bundle savedInstanceState)
  {
  ... Code ...
  
      calendar.DateChange += (s, args) =&gt;
      {
          var year = args.Year;
          var month = args.Month + 1;
          var dayOfMont = args.DayOfMonth;
  
          var date = new DateTime(year, month, dayOfMont);
  
          var myReservations = new Intent(this, typeof(CreateReservationTimeslotScreen));
          myReservations.PutExtra("selectedDate", date.Ticks);
          StartActivity(myReservations);
      };
  }
  </code></pre>
  
  <p>Now that I have switched to MvvmCross, I would like to have my ViewModel start the new activity instead.</p>
  
  <p>Im not sure how to do this, since the ViewModel should be OS and UI agnostic. </p>
  
  <p>The "args" argument is of type CalendarView.DateChangeEventArgs, which is Android specific, so I cant use that in the ViewModel. It derives from System.EventArgs, so maybe I could use that instead. I am thinking that there must be a simpler way.</p>
  
  <p>A thought that I had was if it is possible to update a property on the ViewModel from the activity, and then execute the switch to the new Activity from there? I'm not sure how this could be accomplished since activites dont have references to their ViewModels.</p>
  
  <p>Any suggestions?</p>
  
  <p>Thanks.</p>