get extention values from proto file
value, err := proto.GetExtension(imp, openrtb.E_Imp) if err != nil { logger.Info("E_imp get err ") } impExt := value.(*openrtb.ImpExt) if len(impExt.GetBillingId()) > 0 { info.billing_id = fmt.Sprint(impExt.GetBillingId()[0]) }
原文：http://www.cnblogs.com/lavin/p/7207821.html