title: What are people using instead of IMultiValueConverters in Windows 8?
body: <p>I'm porting an existing WPF application to a Windows 8 application.</p>
  
  <p>In the WPF application we make considerable use of MultiValue convertors to allow us to create values that are combinations of UI element properties and viewmodel properties (the weight of a hippo object and the actualWidth of an itemscontrol) to achieve nice UI effects.</p>
  
  <p>Windows 8, however, doesn't have a MultiValue convertor.  </p>
  
  <p>Since I'm porting an application I don't really want to  significantly change my viewmodels or Xaml.</p>
  
  <p>How can I replicate Multivalue controller functionality with a minimum amount of pain and rewriting?</p>