WPF : Hierarchical data in a datagrid

Hi,

I have a hierarchical data structure that I would like to display in a grid.

Attachment 36016

I have a list of functions and each function in the list contains a list of parameters and I would like to display this list of functions in a grid like above.
What is the best graphics component to do this? A Datagrid, a TreeListView?
And especially how to bind my data on this component?
I'm having a lot of trouble ...

Does anyone among you have a similar example to submit to me?

Thanks