1.IOC简介

IOC(Inversion of Control)， 控制反转

DI (Dependency Injection)，依赖注入

IOC的基本概念是：不创建对象，但是描述创建它们的方式。在代码中不直接与对象和服务连接，但在配置文件中描述哪一个组件需要哪一项服务。容器负责将这些联系在一起。

2.Unity引入

3.创建单例模式容器类

using Microsoft.Practices.Unity;
using Microsoft.Practices.Unity.Configuration;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace UnityIocTest
{
    /// <summary>
    /// Unity IOC单例模式
    /// </summary>
    public class UnitySingleton
    {
        //单例
        private static UnitySingleton instance;

        //ioc容器
        public IUnityContainer container;

        //获取单例
        public static UnitySingleton getInstance()
        {
            if (instance == null || instance.container == null)
            {
                string configFile = "Unity.config";
                var fileMap = new ExeConfigurationFileMap { ExeConfigFilename = configFile };
                //从config文件中读取配置信息
                Configuration configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
                //获取指定名称的配置节
                UnityConfigurationSection section = (UnityConfigurationSection)configuration.GetSection("unity");
                instance = new UnitySingleton()
                {
                    //container = new UnityContainer().LoadConfiguration((UnityConfigurationSection)ConfigurationManager.GetSection("unity"), "MyContainer")
                    container = new UnityContainer().LoadConfiguration(section, "MyContainer")
                    //container = new UnityContainer()
                };
                //instance.container.RegisterType<IExampleClass, ExampleClass>();
            }
            return instance;
        }

        //IOC注入实体
        public static T GetInstanceDAL<T>()
        {
            return getInstance().container.Resolve<T>();
        }
    }
}

此处是将Unity config配置单独成一个文件，方便管理。

4.添加IOC相关类

接口类

public interface IExampleClass
{
    void DoHelloWord();
}

具体实现类

    public class ExampleClass : IExampleClass
    {
        public void DoHelloWord()
        {
            Console.WriteLine("Hello Word!");
        }
    }

实现类扩展

    public class DIExampleClass
    {
        //属性注入
        [Dependency]
        public IExampleClass example { get; set; }

        private IExampleClass testInject;

        public void DoWork()
        {
            example.DoHelloWord();
            testInject.DoHelloWord();
        }

        //方法注入
        [InjectionMethod]
        public void Initialize(IExampleClass instance)
        {
            testInject = instance;
        }
    }

5.添加配置文件Unity.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,Microsoft.Practices.Unity.Configuration" />
  </configSections>
  <unity>
    <!--定义类型别名-->
    <aliases>
      <add alias="IExampleClass" type="UnityIocTest.IExampleClass,UnityIocTest" />
      <add alias="ExampleClass" type="UnityIocTest.ExampleClass,UnityIocTest" />
    </aliases>
    <!--容器-->
    <container name="MyContainer">
      <!--映射关系-->
      <!--<register type="IExampleClass"  mapTo="ExampleClass"></register>-->
      <register type="UnityIocTest.IExampleClass,UnityIocTest"  mapTo="UnityIocTest.ExampleClass,UnityIocTest"></register>
    </container>
  </unity>
</configuration>

6.函数调用

    class Program
    {
        static void Main(string[] args)
        {
            //var dao = UnitySingleton.GetInstanceDAL<IExampleClass>();
            var dao = UnitySingleton.GetInstanceDAL<DIExampleClass>();
            dao.DoWork();
            Console.ReadLine();
        }
    }

7.结果显示

Hello Word!

Hello Word!

原文地址：https://www.cnblogs.com/sylone/p/9483511.html