<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,Microsoft.Practices.Unity.Configuration"/>
  </configSections>
  
  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <container>
      <!--register type="full class name,namespace"-->
      <register type="UnityTest.ISqlHelper,UnityTest" mapTo="UnityTest.MysqlHelper,UnityTest">
        <lifetime type="singleton"/>
      </register>
    </container>
  </unity>
</configuration>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UnityTest
{
    public interface ISqlHelper
    {
         string SqlConnection();
    }

    public interface IOtherHelper
    {
        string GetSqlConnection();
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UnityTest
{
    public class MssqlHelper : ISqlHelper
    {
        public string SqlConnection()
        {
            return "this mssql.";
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UnityTest
{
    public class MysqlHelper : ISqlHelper
    {
        public string SqlConnection()
        {
            return "this mysql.";
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UnityTest
{
    public class MyOtherHelper : IOtherHelper
    {
        ISqlHelper sql;
        public MyOtherHelper(ISqlHelper sql)
        {
            this.sql = sql;
        }
        public string GetSqlConnection()
        {
            return this.sql.SqlConnection();
        }


    }
}

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


namespace UnityTest
{
    class Program
    {
        static void Main(string[] args)
        {
            IUnityContainer mycontainer = new UnityContainer();


            //已有对象实例的配置容器注册
            // MysqlHelper d = new MysqlHelper();
            //mycontainer.RegisterInstance<ISqlHelper>(d);

            //类型的配置容器注册
            //mycontainer.RegisterType<ISqlHelper, MysqlHelper>();

            //配置文件注册
            UnityConfigurationSection section = (UnityConfigurationSection)ConfigurationManager.GetSection("unity");
            section.Configure(mycontainer);
            //mycontainer.LoadConfiguration(); 

            //调用依赖
            ISqlHelper mysql = mycontainer.Resolve<ISqlHelper>();
            Console.WriteLine(mysql.SqlConnection());

            //构造函数注入
            mycontainer.RegisterType<IOtherHelper, MyOtherHelper>();
            IOtherHelper other = mycontainer.Resolve<IOtherHelper>();
            Console.WriteLine(other.GetSqlConnection());

            Console.ReadKey();

        }
    }
}