public IActionResult FlowBalanceDisplay()
{
List <Double> record = new List <Double>(); //double类型的List，存放一个余额，一个利息
record = cardServive.FlowBalanceService((int)DAndC().Dcid); //这里需要service返回一个余额，一个利息
ViewBag.rate = record[0];
ViewBag.balance = record[1];
return(View(ViewBag));
}