1.IOC簡介

IOC(Inversion of Control)， 控制反轉

DI (Dependency Injection)，依賴註入

IOC的基本概念是：不創建對象，但是描述創建它們的方式。在代碼中不直接與對象和服務連接，但在配置文件中描述哪一個組件需要哪一項服務。容器負責將這些聯系在一起。

2.Unity引入

3.創建單例模式容器類

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單例模式 
    /// </summary>
    public class UnitySingleton
    {
        //單例
        private static UnitySingleton instance;

        //ioc容器
        public IUnityContainer container;

        //獲取單例
        public static UnitySingleton getInstance()
        {
            if (instance == null || instance.container == null)
            {
                string configFile = "Unity.config";
                var fileMap = new ExeConfigurationFileMap { ExeConfigFilename = configFile };
                //從config文件中讀取配置信息
                Configuration configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
                //獲取指定名稱的配置節
                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註入實體
        public static T GetInstanceDAL<T>()
        {
            return getInstance().container.Resolve<T>();
        }
    }
}

此處是將Unity config配置單獨成一個文件，方便管理。

4.添加IOC相關類

接口類

public interface IExampleClass
{
    void DoHelloWord();
}

具體實現類

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

實現類擴展

    public class DIExampleClass
    {
        //屬性註入
        [Dependency]
        public IExampleClass example { get; set; }
        
        private IExampleClass testInject;

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

        //方法註入
        [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>
    <!--定義類型別名-->
    <aliases>
      <add alias="IExampleClass" type="UnityIocTest.IExampleClass,UnityIocTest" />
      <add alias="ExampleClass" type="UnityIocTest.ExampleClass,UnityIocTest" />
    </aliases>
    <!--容器-->
    <container name="MyContainer">
      <!--映射關系-->
      <!--<register type="IExampleClass"  mapTo="ExampleClass"></register>-->
      <register type="UnityIocTest.IExampleClass,UnityIocTest"  mapTo="UnityIocTest.ExampleClass,UnityIocTest"></register>
    </container>
  </unity>
</configuration>

6.函數調用

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

7.結果顯示

Hello Word!

Hello Word!

Unity IOC框架使用實例