binding datagrid field on data virtualization

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C#5.0

Hello everybody

i found this solution for my data virtualization

http://www.zagstudio.com/blog/378#.VX5yb_0w9aR

but i have a problem:
i use a datagrid for show my data
and i have this kind of error:

BindingExpression path error: ‘Id’ property not found on ‘object’ ”DataWrapper`1′ (HashCode=67090807)’. BindingExpression:Path=Id; DataItem=’DataWrapper`1′ (HashCode=67090807); target element is ‘TextBlock’ (Name=”); target property is ‘Text’ (type ‘String’)

how can i use a binding for my field?

thank u for your help
have a nice day