Programmic technics to reduce viewstate in ASP.NET 2.0?

[Jéjé]

Hi,

I'm looking for articles or sample code to reduce the viewstate usage in
ASP.NET 2
I want to use the treeview + gridview to create a hierarchical display of my
data.
The grid(s) can be sorted and paged.
the tree content and grid content come from a database.
I'm using datasets and I cache these datasets to improve the performance.

This works fine if the entire viewstate is in the page.

But I want to reduce it by refreshing the grids during callbacks.

What are the events to implement?
when to do to which action?

I don't want to use server side viewstate storage.
I can, but I'm looking for a solution to not do this.

thanks.

Jerome.