关于Linq 中用select 处理Null或"" 的有关问题

关于Linq 中用select 处理Null或"" 的问题
有这样一条语句

  cmbOutbMaterBNo.DisplayMember = "OutbMaterBNo";
  cmbOutbMaterBNo.ValueMember = "OutbMaterBNo";

  var cli = (from c in bContTab.GetAll_ContNoBySortCode("C")
  where c.ContNo == cmbContNo.SelectedValue.ToString()
  select c.SortCode ).Distinct().ToList();


  cmbOutbMaterBNo.DataSource = cli;// 这是combox绑定


其中 bContTab.GetAll_ContNoBySortCode("C") 返回的事自定义类的list 如果select 中的c.sortcode 出现null 就会提示"数据为空! 不能对空值调用此方法或属性"
 

[解决办法]
var cli = (from c in bContTab.GetAll_ContNoBySortCode("C")
where c.ContNo == cmbContNo.SelectedValue.ToString()
select c.SortCode==null?"":c.SortCode).Distinct().ToList();

[解决办法]
var cli = (from c in bContTab.GetAll_ContNoBySortCode("C")
where c.ContNo == cmbContNo.SelectedValue.ToString()
select c.SortCode??"").Distinct().ToList();