在LINQ中使用Max函数

我正在尝试将这个sql转换为我的LINQ查询，并且遇到了很多问题

select Heading,CreatedBy,ReleaseID, MAX(PublishDate)
from Releases
group by Heading,CreatedBy,ReleaseID

我需要以这种LINQ格式使用此查询

  List<RelData> cmsPress = (from Release in dataContext.Releases
                                        select new RelData
                                        {

                                            Heading = Release.Heading,
                                            ReleaseID = Release.ReleaseID,
                                            CreatedBy = Release.CreatedBy,
                                            PublishDate =   Release.PublishDate.ToShortDateString()
                                        }).ToList();

List cmsPress=（来自dataContext.Releases中的Release
选择新数据
{
标题=发布。标题，
ReleaseID=Release.ReleaseID，
CreatedBy=Release.CreatedBy，
PublishDate=Release.PublishDate.ToSortDateString（）
}).ToList（）；

类似这样的内容：

List<RelData> cmsPress = (from Release in dataContext.Releases
    group Release by new { Release.Heading, Release.ReleaseID, Release.CreatedBy } into g
    select new RelData
    {                                              
        Heading = g.Key.Heading,
        ReleaseID = g.Key.ReleaseID,
        CreatedBy = g.Key.CreatedBy,
        PublishDate = g.Max(x => x.PublishDate).ToShortDateString()
    }).ToList(); 

List cmsPress=（来自dataContext.Releases中的Release
按新的{Release.Heading，Release.ReleaseID，Release.CreatedBy}将发布分组到g中
选择新数据
{                                              
Heading=g.Key.Heading，
ReleaseID=g.Key.ReleaseID，
CreatedBy=g.Key.CreatedBy，
PublishDate=g.Max（x=>x.PublishDate）.toSortDateString（）
}).ToList（）；