List<List<int>> array = new List<List<int>> { new List<int>{1, 40, 2}, new List<int>{1 ,40 ,3}, new List<int>{1 ,70, 7}, new List<int>{1, 90, 4}, new List<int>{2 ,40, 1}, new List<int>{2 ,40, 4} }; var list = from a in array group a by new { Item1 = a[0], Item2 = a[1] } into g select new { g.Key.Item1, g.Key.Item2, Item3 = g.Sum(s => s[2]) }; foreach (var item in list) { Console.WriteLine(item.Item1 + "\t" + item.Item2 + "\t" + item.Item3); }
List<List<int>> array = new List<List<int>> { new List<int>{1, 40, 2}, new List<int>{1 ,40 ,3}, new List<int>{1 ,70, 7}, new List<int>{1, 90, 4}, new List<int>{2 ,40, 1}, new List<int>{2 ,40, 4} }; var list = from a in array group a by new { Item1 = a[0], Item2 = a[1] } into g select new { g.Key.Item1, g.Key.Item2, Item3 = g.Sum(s => s[2]) }; foreach (var item in list) { Console.WriteLine(item.Item1 + "\t" + item.Item2 + "\t" + item.Item3); }
我個人推薦使用List<Tuple<int, int, int>>而非List<List<int>>這樣避免索引超出範圍的問題至於你用的List<List<string>>這字串根本沒發計算，還得轉換成數值型別