public async Task <IActionResult> BuyAtNow([FromServices] CartBLL service, int goodsID, int qty)
        {
            //将所有的商品设为不选中
            await service.SetAllChecked(1, 0);

            //然后将当前商品的数量设为指定数量并且选中
            return(MyJsonResult(await service.SetQty(1, goodsID, qty)));
        }
 public async Task SetAllChecked([FromServices] CartBLL service, int selected)
 {
     await service.SetAllChecked(1, selected);
 }