先把需要过滤的条件封转成list
List <A> List = new List <A>();
//分组查询
var P= List
.GroupBy(x => new { x.Age, x.Sex })
.Select(group => new {
Stu= group.Key, Amount= group.sum(x=>x.FAmount)
});
//遍历集合
foreach (var a in P) {
int Amount = p.Amount;
int Age = p.Stu.Age
}