與和

Question

分組數據我有以下列表：

mat.Add(new Material() { ID = 1, ProdName = "Cylinder", Weight=23, Discontinued='N' }); 
mat.Add(new Material() { ID = 2, ProdName = "Gas", Weight = 25, Discontinued='N' }); 
mat.Add(new Material() { ID = 3, ProdName = "Match", Weight = 23, Discontinued='N' }); 

我想要的結果：

2 Products have Weight 23 and Discontinued N 
1 Product have Weigth 25 Discontinued N 

Answer 1

目前還不清楚到底是什麼你實際上分組通過 - 它是既重和停產狀態？如果是這樣，你可以這樣做：

var query = mat.GroupBy(material => 
         new { material.Weight, material.Discontinued }); 

foreach (var result in query) 
{ 
    Console.WriteLine("{0} products have {1}", result.Count(), result.Key); 
} 

Answer 2

Got it！

.GroupBy(re => new { re.Weight, re.Discontinued }) 
      .Select(grp => new { CXXX = group.Key, Count = grp.Count() 

Answer 3

「just」group by Discontinued。

類似於： var result = mat.GroupBy（a => new {a.Weight，a.Discontinued}）。選擇（b => new b.Key.Weight，b.Key.Discontinued，Count = b.Count（）}）;