private ItemFlow BidItemFlow(List<ItemFlow> itemFlows)
{
if (itemFlows == null || itemFlows.Count == 0)
return null;
var q1 = itemFlows.Where(i => i.Flow.OrderTime <= DateTime.Now && i.ReqQty > 0).ToList();
if (q1.Count == 0)
return null;
if (q1.Count == 1)
return q1[0];
//todo
return q1[0];
}