何位大哥有关系c#接口 解耦 的实例啊

public interface IClass1{  void Info();}public class Class2 : IClass1{   public void Info(){//...     System.Console.WriteLine("it's Class2!");   }}public class Class3 : IClass1{   public void Info(){//...     System.Console.WriteLine("it's a Class3!");   }}public static void Main(){    IClass1 cls = new Class2();    cls.Info();    cls = new Class3();    cls.Info();}