C# 使用Linq

using System;
using System.Linq;

namespace ConsoleApplication21
{
    public class Product
    {
        public int ProductID { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public decimal Price { get; set; }
        public string Category { set; get; }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Product[] products = {
                new Product {Name = "西瓜", Category = "水果", Price = 2.3M},
                new Product {Name = "苹果", Category = "水果", Price = 4.9M},
                new Product {Name = "空心菜", Category = "蔬菜", Price = 2.2M},
                new Product {Name = "地瓜", Category = "蔬菜", Price = 1.9M}
            };
            var results = from product in products
                          orderby product.Price descending
                          select new { product.Name, product.Price };

            var res2 = products.Where(r=>r.Name=="地").Count();
            Console.WriteLine(res2);
            var res1 = products.Single(g => g.Name == "地瓜");
            Console.WriteLine("商品：{0}，价钱：{1}", res1.Name, res1.Price);
            var res = products.Sum(p => p.Price);

            /*
            //打印价钱最高的三个商品
            int count = 0;
            foreach (var p in results)
            {
                Console.WriteLine("商品：{0}，价钱：{1}", p.Name, p.Price);
                if (++count == 3) break;
            }
            Console.ReadKey();
            */
        }
    }
}