title: WPF: Binding DataGrid to a list<Product> having a DataGridComboBoxColumn bound to a list<Category>?
body: <p>I have a DataGrid with ItemsSource set to a list of products and
  I have a DataGridComboBoxColumn inside the DataGrid with ItemsSource set to a list of categories. That way I want the user to choose a certain category for each product.</p>
  
  <p>I always get the binding error: </p>
  
  <p>BindingExpression path error: 'Categories' property not found on 'object' ''Product' (Hash)</p>
  
  <p>Well I do not want to make the Category list part of the Product entity as 1:N relation, although it would work that way.</p>
  
  <p>I want to keep them separate.</p>
  
  <p>Anyone knows a workaround?</p>