如何在 Linq GroupBy 中选择前 N 行

希望你能在这里帮助我。 我有一个预订列表，我想在其中获取每组旅游运营商中的前两行。

这是数据示例：

List<Booking> list = new List<Booking>();
        list.Add(new Booking() { BookingNo = "31111111", DepDate = new DateTime(2011, 5, 1), TourOperator = "SPI" });
        list.Add(new Booking() { BookingNo = "32222222", DepDate = new DateTime(2011, 5, 2), TourOperator = "SPI" });
        list.Add(new Booking() { BookingNo = "33333333", DepDate = new DateTime(2011, 5, 3), TourOperator = "SPI" });
        list.Add(new Booking() { BookingNo = "34444444", DepDate = new DateTime(2011, 5, 4), TourOperator = "SPI" });
        list.Add(new Booking() { BookingNo = "35555555", DepDate = new DateTime(2011, 5, 5), TourOperator = "SPI" });
        list.Add(new Booking() { BookingNo = "36666666", DepDate = new DateTime(2011, 5, 6), TourOperator = "SPI" });
        list.Add(new Booking() { BookingNo = "11111111", DepDate = new DateTime(2011, 5, 1), TourOperator = "VIN" });
        list.Add(new Booking() { BookingNo = "12222222", DepDate = new DateTime(2011, 5, 2), TourOperator = "VIN" });
        list.Add(new Booking() { BookingNo = "13333333", DepDate = new DateTime(2011, 5, 3), TourOperator = "VIN" });
        list.Add(new Booking() { BookingNo = "14444444", DepDate = new DateTime(2011, 5, 4), TourOperator = "VIN" });
        list.Add(new Booking() { BookingNo = "15555555", DepDate = new DateTime(2011, 5, 5), TourOperator = "VIN" });
        list.Add(new Booking() { BookingNo = "16666666", DepDate = new DateTime(2011, 5, 6), TourOperator = "VIN" });
        list.Add(new Booking() { BookingNo = "17777777", DepDate = new DateTime(2011, 5, 7), TourOperator = "VIN" });

我有这个 Linq，但它只给我每个组中的第一个预订：

List<Booking> yetAnotherList = list.GroupBy(row => row.TourOperator)
            .Select(g => g.OrderBy(row => row.DepDate).First()).ToList();

我希望得到的数据是这样的：

31111111, 2011-05-01, SPI
32222222, 2011-05-02, SPI
11111111, 2011-05-01, 车辆识别号
12222222, 2011-05-02, 车辆识别号

Thanks.

Replace First() with Take(2)并使用SelectMany():

List<Booking> yetAnotherList = 
                 list.GroupBy(row => row.TourOperator)
                     .SelectMany(g => g.OrderBy(row => row.DepDate).Take(2)) 
                     .ToList();

Update: 忘记了SelectMany第一次。您想要展平结果（其中SelectMany是），否则你会得到一个列表IEnumerables.