帮助使用Linq表达式返回基于字段计数的字符串列表

试试这样的:

var topComments = from comment in Comments
                  group comment by comment.Category into grp
                  orderby grp.Count() descending
                  select grp.Key;

var topFive = topComments.Take(5);

你可以用这样的东西:

var query = comments
    .GroupBy(comment => comment.Category)
    .OrderByDescending(g => g.Count())
    .Select(g => g.Key)
    .Take(5);