safaribook-pro-aspnet-mvc3/chap5_essential_language_fe.../essential_csharp_features/Program.cs

79 lines
2.3 KiB
C#

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using automatically_implemented_properties;
namespace automatically_implemented_properties
{
class Program
{
static void Main(string[] args)
{
Product[] products =
{
new Product {Name = "Kayak", Category = "Watersports", Price = 275M},
new Product {Name = "Lifejacket", Category = "Watersports", Price = 48.95M},
new Product {Name = "Soccer ball", Category = "Soccer", Price = 19.50M},
new Product {Name = "Corner flag", Category = "Soccer", Price = 34.95M}
};
var results = from product in products
orderby product.Price descending
select new
{
product.Name,
product.Price
};
int count = 0;
// print out the names
foreach (var p in results)
{
Console.WriteLine("Item: {0}, Cost: {1}", p.Name, p.Price);
if (++count == 3)
{
break;
}
}
}
}
public static class MyExtensionMethod
{
public static decimal TotalPrices(this IEnumerable<Product> productEnum)
{
decimal total = 0;
foreach (Product prod in productEnum)
{
total += prod.Price;
}
return total;
}
public static IEnumerable<Product> FilterByCategory(this IEnumerable<Product> productEnum,
string categoryParam)
{
foreach (Product prod in productEnum)
{
if (prod.Category == categoryParam)
{
yield return prod;
}
}
}
public static IEnumerable<Product> Filter(this IEnumerable<Product> productEnum,
Func<Product, bool> selectorParam)
{
foreach (Product prod in productEnum)
{
if (selectorParam(prod))
{
yield return prod;
}
}
}
}
}