大話設計-模板方法模式

在基類定義演算法的結構，具體實現延遲到子類。

using System;
namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            TestPaper testPaperA = new TestPaperA();
            testPaperA.TestQuestion1();
            testPaperA.TestQuestion2();
            testPaperA.TestQuestion3();
            TestPaper testPaperB = new TestPaperB();
            testPaperB.TestQuestion1();
            testPaperB.TestQuestion2();
            testPaperB.TestQuestion3();
        }
    }

    class TestPaper
    {
        // 把骨架定義下來，只有答案不同，讓子類實現具體答案。
        public void TestQuestion1()
        {
            Console.WriteLine("題目1：XXXXXXYYYYXXXMMM");
            Console.WriteLine($"題目1答案：{Answer1()}");
        }
        protected virtual string Answer1() { return ""; }    
                
        public void TestQuestion2()
        {
            Console.WriteLine("題目2：IIIPPPKKKKK");
            Console.WriteLine($"題目2答案：{Answer2()}");
        }
        protected virtual string Answer2() { return ""; }

        public void TestQuestion3()
        {
            Console.WriteLine("題目3：UUUUKKKKOOO");
            Console.WriteLine($"題目3答案：{Answer3()}");
        }
        protected virtual string Answer3() { return ""; }
    }

    class TestPaperA : TestPaper
    {
        protected override string Answer1()
        {
            return "a";
        }
        protected override string Answer2()
        {
            return "b";
        }
        protected override string Answer3()
        {
            return "c";            
        }
    }
    class TestPaperB : TestPaper
    {
        protected override string Answer1()
        {
            return "b";
        }
        protected override string Answer2()
        {
            return "c";
        }
        protected override string Answer3()
        {
            return "a";
        }
    }
}

using System;
namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            ConcreteClass concreteClass = new ConcreteClass();
            concreteClass.TemplateMethod();
        }
    }  

   abstract class AbstractClass
    {
        public abstract void PrimitiveOperation1();
        public abstract void PrimitiveOperation2();
        public void TemplateMethod()
        {
            PrimitiveOperation1();
            PrimitiveOperation2();
            Console.WriteLine("");
        }
    }

    class ConcreteClass : AbstractClass
    {
        public override void PrimitiveOperation1()
        {
            Console.WriteLine("具體操作1");
        }

        public override void PrimitiveOperation2()
        {
            Console.WriteLine("具體操作2");
        }
    }
}