Frame Design (I.)

Define interfaces:

 Public Interface ITest    {        double  getprice ();    }

A class implements an interface:

 Public class test1:itest    {        publicdouble  getprice ()        {            return0.32 ;        }    }

To define a shell entity class:

 Public class Test    {        private  ITest ITest;          Public Test (ITest ITest)        {            this. Itest = Itest;        }          Public Double GetPrice ()        {            returnthis. Itest.getprice ();        }    }

Call:

class program    {        staticvoid Main (string[] args)        {            new Test (  New  Test1 ());             var returnval = test. GetPrice ();            Console.Write (returnval);            Console.read ();        }    }

Frame Design (I.)