c# - LINQ 联合和不同

Question

我有一个 C# .Net Web 应用程序，我正在使用以下 LINQ 查询来获取用户创建的或具有各种用户角色的不同提案列表。即使在 Union 和 Distinct 之后，要返回的列表也包含相同提案的重复内容。我做错了什么？

      var thereturn = FindAll(DetachedCriteria.For<Proposal>(),
                             new Order("CreateDate", false));

     //get the proposals that aUser created
     IList<Proposal> it = 
                thereturn.Where(proposal => proposal.CreatedBy.Equals(aUser)).ToList();

     //get the proposals that aUser is a BOE Author
     IList<Proposal> it2 =
          thereturn.Where(proposal =>
              proposal.BOEs.Any(boe =>
                  boe.Users.Where(a => a.Name == aUser).Any())).ToList();
     //get all other proposals that aUser is on
     IList<Proposal> it3 = 
          thereturn.Where(proposal =>
              proposal.Users.Where(o => o.Name == aUser).Any()).ToList();
     //now union with all other proposals that aUser is on
     return it3.Union(it).Union(it2).
               OrderByDescending(o=>o.CreateDate).Distinct().ToList();

Answer 1

Proposal 类的定义是什么？您可能对 Proposal 类的默认相等运算符有疑问。 As msdn says about Distinct :

Returns distinct elements from a sequence by using the default equality comparer to compare values.

编辑:换句话说，您是否有 Equals 和/或 GetHashCode 的自定义实现？