Linq：GroupBy，Sum和Count我有一系列產(chǎn)品public class Product {
public Product() { }
public string ProductCode {get; set;}
public decimal Price {get; set; }
public string Name {get; set;}}現(xiàn)在，我想根據(jù)產(chǎn)品代碼對(duì)集合進(jìn)行分組，并返回一個(gè)對(duì)象，其中包含每個(gè)代碼的名稱(chēng)，數(shù)量或產(chǎn)品以及每個(gè)產(chǎn)品的總價(jià)格。public class ResultLine{
public ResultLine() { }
public string ProductName {get; set;}
public string Price {get; set; }
public string Quantity {get; set;}}所以我使用GroupBy按ProductCode進(jìn)行分組，然后計(jì)算總和并計(jì)算每個(gè)產(chǎn)品代碼的記錄數(shù)。這是我到目前為止：List<Product> Lines = LoadProducts(); List<ResultLine> result = Lines
.GroupBy(l => l.ProductCode)
.SelectMany(cl => cl.Select(
csLine => new ResultLine
{
ProductName =csLine.Name,
Quantity = cl.Count().ToString(),
Price = cl.Sum(c => c.Price).ToString(),
})).ToList<ResultLine>();由于某種原因，總和正確完成但計(jì)數(shù)始終為1。Sampe數(shù)據(jù)：List<CartLine> Lines = new List<CartLine>();
Lines.Add(new CartLine() { ProductCode = "p1", Price = 6.5M, Name = "Product1" });
Lines.Add(new CartLine() { ProductCode = "p1", Price = 6.5M, Name = "Product1" });
Lines.Add(new CartLine() { ProductCode = "p2", Price = 12M, Name = "Product2" });樣本數(shù)據(jù)的結(jié)果：Product1: count 1 - Price:13 (2x6.5)Product2: count 1 - Price:12 (1x12)產(chǎn)品1應(yīng)該有count = 2！我嘗試在一個(gè)簡(jiǎn)單的控制臺(tái)應(yīng)用程序中模擬這個(gè)，但我得到以下結(jié)果：Product1: count 2 - Price:13 (2x6.5)Product1: count 2 - Price:13 (2x6.5)Product2: count 1 - Price:12 (1x12)產(chǎn)品1：應(yīng)該只列出一次...上面的代碼可以在pastebin上找到：http：//pastebin.com/cNHTBSie
Linq：GroupBy，Sum和Count
當(dāng)年話(huà)下
2019-08-08 16:03:24
