委托的应用-模板和回调

一，模板方法

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;


namespace JSONTest
{ 
    class Program
    {
        static void Main()
        {
            ProductFactory productFactory = new ProductFactory();
            WrapFactory wrapFactory = new WrapFactory();
            Func<Product> func1 = new Func<Product>(productFactory.MakePizza);
            Func<Product> func2 = new Func<Product>(productFactory.MakeToyCar);

            Box box1 = wrapFactory.WrapProduct(func1);
            Box box2 = wrapFactory.WrapProduct(func2);

            Console.WriteLine(box1.Product.Name);
            Console.WriteLine(box2.Product.Name);
            Console.ReadLine();
        }
    }
    class Product
    {
        public string Name { get; set; }
    }
    class Box
    {
        public Product Product { get; set; }
    }
    class WrapFactory
    {
        public Box WrapProduct(Func<Product> getProduct)
        {
            Box box = new Box();
            Product product = getProduct.Invoke();
            box.Product = product;
            return box;
        }//模板方法，接受委托类型参数
    }
    class ProductFactory
    {
        public Product MakePizza()
        {
            Product product = new Product();
            product.Name = "Pizza";
            return product;
        }
        public Product MakeToyCar()
        {
            Product product = new Product();
            product.Name = "ToyCar";
            return product;
        }
    }
}

二。回调方法

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;


namespace JSONTest
{ 
    class Program
    {
        static void Main()
        {
            ProductFactory productFactory = new ProductFactory();
            WrapFactory wrapFactory = new WrapFactory();
            Func<Product> func1 = new Func<Product>(productFactory.MakePizza);
            Func<Product> func2 = new Func<Product>(productFactory.MakeToyCar);

            Logger logger = new Logger();
            Action<Product> log = new Action<Product>(logger.Log) ;
            Box box1 = wrapFactory.WrapProduct(func1,log);
            Box box2 = wrapFactory.WrapProduct(func2,log);

            Console.WriteLine(box1.Product.Name);
            Console.WriteLine(box2.Product.Name);
            Console.ReadLine();
        }
    }
    class Logger
    {
        public void Log(Product product)
        {
            Console.WriteLine("Product{0}created at{1},price is {2}.", product.Name, DateTime.UtcNow, product.Price);
        }
    }

    class Product
    {
        public string Name { get; set; }
        public double Price { get; set; }
    }
    class Box
    {
        public Product Product { get; set; }
    }
    class WrapFactory
    {
        public Box WrapProduct(Func<Product> getProduct,Action<Product>logCallback) //Func<Product> getProduct Product是返回值类型，Action<Product>logCallback Product是传入参数
        {
            Box box = new Box();
            Product product = getProduct.Invoke();
            if(product.Price>50)
            {
                logCallback(product);
            }
            box.Product = product;
            return box;
        }//模板方法，接受委托类型参数
    }
    class ProductFactory
    {
        public Product MakePizza()
        {
            Product product = new Product();
            product.Name = "Pizza";
            product.Price = 12;
            return product;
        }
        public Product MakeToyCar()
        {
            Product product = new Product();
            product.Name = "ToyCar";
            product.Price = 100;
            return product;
        }
    }
}