将匿名对象添加到匿名列表

Question

I have a list of anonymous types stored in b (which comes from a list) and i want to add a new object to the list. When i try to add a new anonymous object to this list i get this error:

The best overloaded method match for 'System.Collections.Generic.List.Add(AnonymousType#1)' has some invalid arguments. And i also get this error: Argument 1: cannot convert from 'AnonymousType#2' to 'AnonymousType#1'

 var b = user.Orders.Select(i => new { id = i.BillingId , text = i.Billing.ToString() }).ToList();
 b.Add(new { id = 0 , text = "New Billing Address" });

Thanks in advance

Answer 1

What type is BillingId ? You may need a suffix on the digit literal, or a cast, or get the Value if it is nullable..