in my point of view, you don't send the datagrid items, you
send it's dataprovider.
What i mean is , how do you populate your datagrid? is it
with an array of objects? is it with a xml file?
You need to iterate on the data provider, one by one and send
it, or more simply you can send all of them encapsulated on an
arraylist but your webservice must know how to read this arraylist.