GridView update problem

[chenhong]

I have a gridview in an aspx page.
I set three column to readonly, two datetime type, one string type.
Now here is something strange.
In the ObjectDataSource1_Updating method.
Two datetime typed columns aren't in the e.InputParameters collection,
but the string type which also set to readonly is in the
e.InputParameters collection.

Any idea what's happening here?

TIA