LINQ - 为匿名类型的只读属性赋值

Question

我想从linq创建一个匿名类型.然后手动更改单个属性(status)的值,​​并将列表作为数据源提供给转发器.但是不要让我这样做因为它是只读的.有什么建议吗？

 var list = from c in db.Mesai
                   join s in db.MesaiTip on c.mesaiTipID equals s.ID
                   where c.iseAlimID == iseAlimID
                   select new
                   {
                       tarih = c.mesaiTarih,
                       mesaiTip = s.ad,
                       mesaiBaslangic = c.mesaiBaslangic,
                       mesaiBitis = c.mesaiBitis,
                       sure = c.sure,
                       condition = c.onaylandiMi,
                       status = c.status
                   };
 foreach (var item in list)
 {
     if (item.condition==null)
     {
          item.status == "Not Confirmed";
     }
 }
 rpCalisanMesai.DataSource = list.ToList();
 rpCalisanMesai.DataBind();

Answer 1

创建列表后,只需设置正确的值,而不是在创建列表后尝试更改值.

var list = from c in db.Mesai
               join s in db.MesaiTip on c.mesaiTipID equals s.ID
               where c.iseAlimID == iseAlimID
               select new
               {
                   tarih = c.mesaiTarih,
                   mesaiTip = s.ad,
                   mesaiBaslangic = c.mesaiBaslangic,
                   mesaiBitis = c.mesaiBitis,
                   sure = c.sure,
                   condition = c.onaylandiMi,
                   status = c.onaylandiMi != null ? c.status : "Not Confirmed"
               };

此外,如果您可以更改属性,您的问题将是执行两次查询:首先在foreach-loop中,然后再次调用list.ToList()(这将创建匿名类型的新实例).