原文地址：http://www.cnblogs.com/leoo2sk/archive/2009/06/17/1504693.html

 

里面有一个例子差了些代码，补全后贴上。

3.1.3 依赖获取

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Xml;//定义了三个接口 IWindow IButton ITextBoxnamespace DependencyLocate{    internal interface IWindow    {        String ShowInfo();    }    internal interface IButton    {        String ShowInfo();    }    internal interface ITextBox    {        String ShowInfo();    }}//实现接口 IWindow， 实现类 WindowsWindow、MacWindownamespace DependencyLocate{    internal sealed class WindowsWindow : IWindow    {        public String Description { get; private set; }        public WindowsWindow()        {            this.Description = "Windows风格窗体";        }        public String ShowInfo()        {            return this.Description;        }    }    internal sealed class MacWindow : IWindow    {        public String Description { get; private set; }        public MacWindow()        {            this.Description = " Mac风格窗体";        }        public String ShowInfo()        {            return this.Description;        }    }}//实现接口 IButton， 实现类 WindowsButton、MacButtonnamespace DependencyLocate{    internal sealed class WindowsButton : IButton    {        public String Description { get; private set; }        public WindowsButton()        {            this.Description = "Windows风格按钮";        }        public String ShowInfo()        {            return this.Description;        }    }    internal sealed class MacButton : IButton    {        public String Description { get; private set; }        public MacButton()        {            this.Description = " Mac风格按钮";        }        public String ShowInfo()        {            return this.Description;        }    }}//实现接口 ITextBox， 实现类 WindowsTextBox、MacTextBoxnamespace DependencyLocate{    internal sealed class WindowsTextBox : ITextBox    {        public String Description { get; private set; }        public WindowsTextBox()        {            this.Description = "Windows风格文本框";        }        public String ShowInfo()        {            return this.Description;        }    }    internal sealed class MacTextBox : ITextBox    {        public String Description { get; private set; }        public MacTextBox()        {            this.Description = " Mac风格文本框";        }        public String ShowInfo()        {            return this.Description;        }    }}namespace DependencyLocate{    internal interface IFactory    {        IWindow MakeWindow();        IButton MakeButton();        ITextBox MakeTextBox();    }}namespace DependencyLocate{    internal sealed class WindowsFactory : IFactory    {        public IWindow MakeWindow()        {            return new WindowsWindow();        }        public IButton MakeButton()        {            return new WindowsButton();        }        public ITextBox MakeTextBox()        {            return new WindowsTextBox();        }    }}namespace DependencyLocate{    internal sealed class MacFactory : IFactory    {        public IWindow MakeWindow()        {            return new MacWindow();        }        public IButton MakeButton()        {            return new MacButton();        }        public ITextBox MakeTextBox()        {            return new MacTextBox();        }    }}namespace DependencyLocate{    internal static class FactoryContainer    {        public static IFactory factory { get; private set; }        /// 
        /// 静态构造函数：        ///     是一个特殊的函数，将在其他所有方法执行之前以及变量或属性被第一次访问之前执行。        ///     这个构造函数是属于类的，而不是属于哪里实例的，就是说这个构造函数只会被执行一次。        ///     也就是在创建第一个实例或引用任何静态成员之前，由.NET自动调用。        ///     可以使用该函数来初始化静态变量，不应该使用实例构造函数初始化静态变量。        /// 地址：https://www.cnblogs.com/aimi/p/5499711.html        /// 
        static FactoryContainer()        {            XmlDocument xmlDoc = new XmlDocument();            xmlDoc.Load("Config.xml");            XmlNode xmlNode = xmlDoc.ChildNodes[1].ChildNodes[0].ChildNodes[0];            if ("Windows" == xmlNode.Value)            {                factory = new WindowsFactory();            }            else if ("Mac" == xmlNode.Value)            {                factory = new MacFactory();            }            else            {                throw new Exception("Factory Init Error");            }        }    }}namespace DependencyLocate{    class Program    {        static void Main(string[] args)        {            IFactory factory = FactoryContainer.factory;            IWindow window = factory.MakeWindow();            Console.WriteLine("创建 " + window.ShowInfo());            IButton button = factory.MakeButton();            Console.WriteLine("创建 " + button.ShowInfo());            ITextBox textBox = factory.MakeTextBox();            Console.WriteLine("创建 " + textBox.ShowInfo());            Console.ReadLine();        }    }}