C#演化类及排序

本文主要介绍 C#从2003至2010中类及排序方法的进步

Product.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace ConsoleApplication2
{
    //c#2003
    public class Product
    {
        string name;
        public string Name
        {
            get { return name; }
        }

        decimal price;
        public decimal Price
        {
            get { return price; }
        }

        public Product(string name, decimal price)
        {
            this.name = name;
            this.price = price;
        }

        public static ArrayList GetSampleProducts()
        {
            ArrayList list = new ArrayList();
            list.Add(new Product("West Side Story", 9.99m));
            list.Add(new Product("Assassiins", 14.99m));
            list.Add(new Product("Frogs", 13.99m));
            return list;
        }

        public override string ToString()
        {
            return string.Format("{0}:{1}", name, price);
        }
    }

    //c#2005
    public class ProductEx
    {
        string name;
        public string Name
        {
            get { return name; }
            private set { name = value; }
        }

        decimal price;
        public decimal Price
        {
            get { return price; }
            private set { price = value; }
        }

        public ProductEx(string name, decimal price)
        {
            Name = name;
            Price = price;
        }

        public static List<ProductEx> GetSampleProducts()
        {
            List<ProductEx> list = new List<ProductEx>();
            list.Add(new ProductEx("West Side Story", 9.99m));
            list.Add(new ProductEx("Assassiins", 14.99m));
            list.Add(new ProductEx("Frogs", 13.99m));
            return list;
        }

        public override string ToString()
        {
            return string.Format("{0}:{1}", name, price);
        }
    }

    //c#2008
    public class ProductExEx
    {
        public string Name
        {
            get;
            private set;
        }

        public decimal Price
        {
            get;
            private set;
        }

        public ProductExEx(string name, decimal price)
        {
            Name = name;
            Price = price;
        }

        ProductExEx() { }

        public static List<ProductExEx> GetSampleProducts()
        {
            return new List<ProductExEx>
            {
                new ProductExEx{Name="West Side Story",Price=9.99m},
                new ProductExEx{Name="Assassins",Price=14.99m},
                new ProductExEx{Name="Frogs",Price=13.99m}
            };               
        }

        public override string ToString()
        {
            return string.Format("{0}:{1}", Name, Price);
        }
    }

    //c#2010
    public class ProductExExEx
    {
        readonly string name;

        public string Name
        {
            get { return name; }       
        }

        readonly decimal price;

        public decimal Price
        {
            get { return price; }           
        }

        public ProductExExEx(string name, decimal price)
        {
            this.name = name;
            this.price = price;
        }    

        public static List<ProductExExEx> GetSampleProducts()
        {
            return new List<ProductExExEx>
            {
                new ProductExExEx(name:"West Side Story",price:9.99m),
                new ProductExExEx(name:"Assassins",price:14.99m),
                new ProductExExEx(name:"Frogs",price:13.99m)
            };
        }

        public override string ToString()
        {
            return string.Format("{0}:{1}", name, price);
        }
    }

}

 

 

program.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
           
            Console.WriteLine("c#2003 sort:");
            ArrayList products = Product.GetSampleProducts();
            products.Sort(new ProductComparer());
            foreach (Product item in products)
            {
                Console.WriteLine(item);
            }

            Console.WriteLine("c#2005 sort:");
            List<ProductEx> productexs = ProductEx.GetSampleProducts();
            productexs.Sort(delegate(ProductEx x,ProductEx y) {return x.Name.CompareTo(y.Name);});

            Console.WriteLine("c#2008 sort:");
            List<ProductExExEx> list = ProductExExEx.GetSampleProducts();                       
            list.Sort((x, y) => x.Name.CompareTo(y.Name));
            foreach (ProductExExEx item in list)
            {
                Console.WriteLine(item);
            }

            Console.WriteLine("c#2010 sort:");
            foreach (ProductExExEx item in list.OrderBy(p => p.Name))
            {
                Console.WriteLine(item);
            }
        }
    }

    class ProductComparer : IComparer
    {
        public int Compare(object x, object y)
        {
            Product first = (Product)x;
            Product second = (Product)y;
            return first.Name.CompareTo(second.Name);
        }
    }

    class ProductExComparer : IComparer<ProductEx>
    {
        public int Compare(ProductEx x,ProductEx y)
        {           
            return x.Name.CompareTo(y.Name);
        }
    }

}