[LINQ] ToDictionary()

對 Dictionary 的認知就是 key、value 組合，所以使用 ToDictionary() 時，很直覺會是需要輸入 key、value，看 MSDN 時發現原來有只輸入 key 的 overload 可以使用，value 會直接是該物件型別

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("--------- 個人原寫法 ---------");
            Dictionary<long, Package> jt = DemoHelper.GetData()
                .ToDictionary(k => k.TrackingNumber, v => v);
            DemoHelper.ShowData(jt);

            Console.WriteLine("--------- ToDictionary() 多載 ---------");
            Dictionary<long, Package> msdn = DemoHelper.GetData()
                .ToDictionary(k => k.TrackingNumber);
            DemoHelper.ShowData(msdn);

        }
    }

    class Package
    {
        public string Company { get; set; }
        public double Weight { get; set; }
        public long TrackingNumber { get; set; }

        public override string ToString()
        {
            return $"{TrackingNumber} ,{Company}, {Weight}";
        }
    }

    static class DemoHelper
    {
        public static List<Package> GetData()
        {
            return
                new List<Package>{
                    new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 89453312L },
                    new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 89112755L },
                    new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 299456122L },
                    new Package { Company = "Adventure Works", Weight = 33.8, TrackingNumber = 4665518773L } };
        }

        public static void ShowData(Dictionary<long, Package> Data)
        {
            foreach (var item in Data)
            {
                Console.WriteLine(item.ToString());
            }
        }
    }
}

參考資料
• ToDictionary()