title: What defines the bindings update order in WPF?
body: <p>I have a piece of WPF/C# code that uses several Bindings:</p>
  
  <ol>
  <li>A combobox is used to select an Account</li>
  <li>The itemssource property of a second combobox is bound to the selected Account. This second combobox is used to select a Contact</li>
  <li>The itemssource property of a grid is bound to the selected Account. This grid contains the selected Account Invoices.</li>
  <li>The Contacts combobox parent DataContext is bound to the selected Invoice.</li>
  <li>The SelectedItem of the Contacts combobox is bound to the InvoiceContact property of the Invoice in the datacontext.</li>
  </ol>
  
  <p>However the bindings are not updated in the order I want them to be. When I select another Account, the ItemsSource property of the Contact combobox change first, then it obviously change the SelectedItem, which changes the InvoiceContact and THEN, the selected Invoice changes...</p>
  
  <p>No need to tell that it messes up the Invoice that was selected.</p>
  
  <p>How can I control the order used to update the Bindings?</p>
  
  <p>Thanks</p>
  
  <p>Alex</p>