正确关闭vb.net中的adodb连接

private adoconnect as new adodb.connection
public adors as new adodb.recordset

public function returnadors(byval column as string) as string
 return adors.fields(column).value.tostring
end function


Public Function ReadData(ByVal strQuery As String, Optional ByVal strWhere As String = vbNullString) As Boolean

        Try

            If ADOConnect.State = ConnectionState.Open Then Call CloseConnection()
            ADOConnect.Open(dsn, user, pass)
            ADORS.Open(strQuery, ADOConnect, ADODB.CursorTypeEnum.adOpenDynamic)
            If not ADORS.EOF  Then Return True

        Catch ex As Exception

            msgbox(ex)

        End Try

        Return False

End Function

public sub closeconnection()
   if adoconnect.state = connectionstate.open then adoconnect.close
end sub

if readdata(\"SELECT NAME FROM USERS WHERE ID = 1\") then
    me.textbox1.text = returnadors(\"NAME\")
end if
call closeconnection