.net Linq：GroupBy、Sum 和 Count

我有一系列产品

public class Product {

   public Product() { }

   public string ProductCode {get; set;}
   public decimal Price {get; set; }
   public string Name {get; set;}
}

现在，我想根据产品代码对集合进行分组，并返回一个对象，其中包含每个代码的名称、编号或产品以及每个产品的总价.

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分组，然后计算总和，并计算每个产品代码的记录数.

这就是我目前的情况:

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>();

For some reason, the sum is done correctly but the count is always 1.

Sampe数据:

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" });

样本数据的结果:

Product1: count 1   - Price:13 (2x6.5)
Product2: count 1   - Price:12 (1x12)

产品1的计数应为2！

我试图在一个简单的控制台应用程序中模拟这一点，但结果如下:

Product1: count 2   - Price:13 (2x6.5)
Product1: count 2   - Price:13 (2x6.5)
Product2: count 1   - Price:12 (1x12)

产品1:应该只列出一次...