C# List Orderby

[yxy10072510329]

var oneGroupChapterList = chapterList.Where(x => x.ProviderId == oneGroup.Key.ProviderId && x.BookId == oneGroup.Key.BookId).ToList<BookChapterInfo>();
                List<BookChapterInfo> allChapter = oneGroupChapterList.OrderBy(c => new { c.DisplayOrder, c.ChapterId }).ToList<BookChapterInfo>();

异常信息：At least one object must implement IComparable.，也就是在OrderBy的时候出的异常，谁知道为什么在线等。。

[q107770540]

var oneGroupChapterList = chapterList.Where(x => x.ProviderId == oneGroup.Key.ProviderId && x.BookId == oneGroup.Key.BookId);
List<BookChapterInfo> allChapter = oneGroupChapterList.OrderBy(c => new { c.DisplayOrder, c.ChapterId }).ToList<BookChapterInfo>();

去掉第一句的.ToList<BookChapterInfo>();
它破坏了 linq 的延迟查询 ，影响了效率

[gomoku]

List<BookChapterInfo> allChapter = oneGroupChapterList.OrderBy(c => c.DisplayOrder * 1000000L + c.ChapterId ).ToList<BookChapterInfo>();

[Peter200694013]

相应类实现IComparable接口

[yizhili]

.NET 不知道 new { c.DisplayOrder, c.ChapterId } 要如何排序
如果要双关键字排序可以用 OrderBy( c=>c.DisplayerColor ).ThenBy( c=>c.ChaptherId )

[wanghui0380]

OrderBy(c => new { c.DisplayOrder, c.ChapterId })

orderby 只允许使用值类型，或已实现了IComparable接口的对象

[yxy10072510329]

yizhili正解，其他童鞋说的可能与我的情况不大对口，结贴给分，谢谢大家！