Unity Injection by factory

app.config.xml

<?xml version="1.0"?>
<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">
    <sectionExtension type="Unity.FactoryConfig.FactoryConfigExtension, Unity.FactoryConfig"/>
    <alias alias="IDbConnection" type="System.Data.IDbConnection, System.Data"/>
    <container>
      <register type="IDbConnection" name="conn123456789">
        <factory type="UnityTestInjection.Program, UnityTestInjection" method="GetConnection"/>
      </register>
    </container>
  </unity>
</configuration>

Program.cs

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

namespace UnityTestInjection
{
    public class Program
    {
        public static System.Data.IDbConnection GetConnection()
        {
            return new System.Data.SqlClient.SqlConnection();
        }

        static void Main(string[] args)
        {
            var unitySection = (UnityConfigurationSection)ConfigurationManager.GetSection("unity");
            var container = new UnityContainer().LoadConfiguration(unitySection);
            var connection = container.Resolve<IDbConnection>("conn123456789");
        }
    }
}

source

Install-Package Unity -Version 2.1.505.2
https://bitbucket.org/ctavares/unityfactoryconfig  or https://github.com/andriniaina/Unity.FactoryConfig
http://stackoverflow.com/questions/9943216/unity-factory-via-xml