设计模式之C#实现(一)--AbstractFactory[4]

                     return b.tostring();

              }

       }

       public class producta2 : iabstractproducta{

              public producta2(){}

              public string showself(){

                     return this.tostring();

              }

              public string showother(iabstractproductb b){

                     return b.tostring();