的GroupBy奇特行爲

Question

爲什麼通過回做集團的所有元素（其實都不止，8種元素在我的情況！[在這裏輸入的形象描述] [1]）

List<Package> packages = new List<Package> { new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 10 }, 
              new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 10}, 
              new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 12 }, 
              new Package { Company = "Contoso Pharmaceuticals", Weight = 9.3, TrackingNumber = 13}, 
              new Package { Company = "Wide World Importers", Weight = 33.8, TrackingNumber = 12 } }; 

IGrouping<long, Package>[] simba_3 = packages.GroupBy(x => 23L).ToArray(); 

simba_3有鍵一個元素= 23和8封裝元素，這裏發生了什麼？

Answer 1

因爲你不正常方式使用GroupBy：

List<Package> packages = new List<Package> { new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 10 }, 
              new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 10}, 
              new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 12 }, 
              new Package { Company = "Contoso Pharmaceuticals", Weight = 9.3, TrackingNumber = 13}, 
              new Package { Company = "Wide World Importers", Weight = 33.8, TrackingNumber = 12 } }; 

var simba_3 = packages.GroupBy(x => x. Weight).ToArray(); 
var simba_4 = packages.GroupBy(x => x. TrackingNumber).ToArray();