框架设计（一）

public interface ITest
    {
        double GetPrice();

    }

public class Test1 : ITest
    {
        public double GetPrice()
        {
            return 0.32;
        }
    }

public class Test
    {
        private ITest Itest;

        public Test(ITest itest)
        {
            this.Itest = itest;
        }

        public double GetPrice()
        {
            return this.Itest.GetPrice();
        }
    }

class Program
    {
        static void Main(string[] args)
        {
            Test test = new Test(new Test1());
            var returnVal = test.GetPrice();
            Console.Write(returnVal);
            Console.Read();
        }
    }