Perhaps the best way is to bind it with a DataSource Control (e.g.
ObjectDataSource or SqlDataSource). That would take care of details
like 'when, how, where' and caching. Please note that DataSource
controls are bound by propertie DataSourceID (and not DataSource).

Alternatively you may hook up RowCreated event and get manual access
by e.Row.FindControl (after ensuring its a data row by e.Row.RowType
== DataControlRowType.DataRow).