1 namespace UnityDemo
2 {
3     public interface IProgrammer
4     {
5         void Working();
6     }
7 }

 1 using System;
 2 
 3 namespace UnityDemo
 4 {
 5     public class CSharp : IProgrammer
 6     {
 7         public void Working()
 8         {
 9             Console.WriteLine("programming C# ...");
10         }
11     }
12 
13     public class VB : IProgrammer
14     {
15         public void Working()
16         {
17             Console.WriteLine("programming VB ...");
18         }
19     }
20 
21     public class Java : IProgrammer
22     {
23         public void Working()
24         {
25             Console.WriteLine("programming Java ...");
26         }
27     }
28 }

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!--<startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2"/>
  </startup>-->

  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,Microsoft.Practices.Unity.Configuration"/>
  </configSections>
  <unity>
    <containers>
      <container name="Programmer">
        <register type="UnityDemo.IProgrammer,UnityDemo"  mapTo="UnityDemo.CSharp,UnityDemo" name="CSharp"></register>
        <register type="UnityDemo.IProgrammer,UnityDemo"  mapTo="UnityDemo.VB,UnityDemo" name="VB"></register>
        <register type="UnityDemo.IProgrammer,UnityDemo"  mapTo="UnityDemo.Java,UnityDemo" name="Java"></register>
      </container>
    </containers>
  </unity>
</configuration>

 1 using Microsoft.Practices.Unity;
 2 using Microsoft.Practices.Unity.Configuration;
 3 using System;
 4 using System.Configuration;
 5 
 6 namespace UnityDemo
 7 {
 8     class Program
 9     {
10         private static IUnityContainer container = null;
11 
12         static void Main(string[] args)
13         {
14             RegisterContainer();
15 
16             var programmer = container.Resolve<IProgrammer>("CSharp");
17             //var programmer = container.Resolve<IProgrammer>("VB");
18             programmer.Working();            
19 
20             Console.ReadKey();
21         }
22 
23         private static void RegisterContainer()
24         {
25             container = new UnityContainer();
26             UnityConfigurationSection config =(UnityConfigurationSection) ConfigurationManager.GetSection(UnityConfigurationSection.SectionName);
27             config.Configure(container, "Programmer");
28         }
29     }
30 }