GroupBy中多列合并一列方法

1. var query=list.GroupBy(t=>new{t....分组字段})

.Select(g=>

new {FROM=g.Key.From,TO=g.Key.To,NUM=g.Count(),Time=g.Key.Time,Body=string.Join(",",g.Select(s=>s.Body).ToArray())})

 

2var list=list.GroupBy(t=>new{ ...分组字段}).Select(p =>new 类 {属性=p.key.值，属性=string.Join(",",p.Select(s=>s.值).ToArray())}