I used to close an open datareader using the try/catch/finally block:
Dim dr As MySqlDataReader = Nothing
Try
dr = DBConnection.callReadingStoredProcedure("my_sp")
Catch ex As Exception
' the caller will handle this
Throw ex
Finally
If dr IsNot Nothing Then dr.Close()
End Try
But I think it should be cleaner (and somewhat faster) to use the "Using" VB keyword:
Using dr As MySqlDataReader = DBConnection.callReadingStoredProcedure("my_sp")
End Using
' dr is surely disposed, but is it closed?
Does the IDispose interface (required by Using) perform a Close on the DataReader?