WPF: Binding DataGrid to a list<Product> having a DataGridComboBoxColumn bound to a list<Category>? -

I have a datagroup with the items set for the list of items and I have a datagrid inside the datagrid that is used for datasource Together with the datagrid, I want to select the user a certain category for each product in this way of categories.

I always get the binding error:

Binding Expression Path Error: 'Object' '' Product '(hash)

Well, I have 1: N Relation As the product unit does not want to make a category list part, it will work that way. Create class with

I

Fixed property such as

  Fixed class value list {public stable IEnumerable & lt; Category & gt; Categories {...}}}  

and use the following to force

  item processing = "{x: static myNs: ValueList. Categories} "/>