.NET MySql does “Using” closes the datareader?

Question

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?

Answer 1

The object will be disposed. Yes, this closes the DataReader.

Answer 2

Reader will be closed, but this is not necessary for underlaying database connection because it is managed with ADO.NET connection pool. Check this answer for more information: C# MySqlConnection won't close