var query=from s in db.SubArea
......此处省略
select new{
....//此处省略
Zhan = db.Customer.Where(c => (db.graveTemp.Where(g => g.subarea == s.Id).Select(g => g.gvid).Contains(c.FgrvId)))
};
//提示错误错误    “System.Linq.IQueryable<int>”不包含“Contains”的定义，并且最佳扩展方法重载 “System.Linq.ParallelEnumerable.Contains<TSource>(System.Linq.ParallelQuery<TSource>, TSource)”的某些参数无效    F:\projects\TombPrj\TombDAL\GraveService.cs    346    60    TombDAL

var query=(from s in db.SubArea
           join g in db.graveTemp on g.subarea equals s.Id select g.gvid)
          .Count(gid => db.Customer.Any(c=>c.FgrvId==gid));

------解决方案--------------------

var query=from s in db.SubArea
......此处省略
select new{
....//此处省略
Zhan = from c in db.Customer
      let subIds=db.graveTemp.Where(g => g.subarea == s.Id).Select(g => g.gvid)
      where subIds.Contains(c.FgrvId)
      select c;
};