設計模式---責任鍊模式（DesignPattern_ChainofResponsibility）

摘錄自：設計模式與遊戲完美開發

十年磨一劍，作者将設計模式理論巧妙地融入到實踐中，以一個遊戲的完整實作呈現設計模式的應用及經驗的傳承 《軒轅劍》之父——蔡明宏、資深遊戲制作人——李佳澤、Product Evangelist at Unity Technologies——Kelvin Lo、信仁軟體設計創辦人—— 賴信仁、資深3D遊戲美術——劉明恺 聯合推薦全書采用了整合式的項目教學，即以一個遊戲的範例來應用23種設計模式的實作貫穿全書，讓讀者學習到整個遊戲開發的全過程和作者想要傳承的經驗，并以淺顯易懂的比喻來解析難以了解的設計模式，讓想深入了解此領域的讀者更加容易上手。

工程GitHub

using UnityEngine;
using System.Collections;

namespace DesignPattern_ChainofResponsibility
{
    // 處理訊息的介面
    public abstract class Handler
    {
        protected Handler m_NextHandler = null;

        public Handler( Handler theNextHandler )
        {
            m_NextHandler = theNextHandler;
        }

        public virtual void HandleRequest(int Cost)
        {
            if(m_NextHandler!=null)
                m_NextHandler.HandleRequest(Cost);
        }
    }
    
    // 處理所負責的訊息1
    public class ConcreteHandler1 : Handler
    {
        private int m_CostCheck = 10;

        public ConcreteHandler1( Handler theNextHandler ) : base( theNextHandler )
        {}

        public override void HandleRequest(int Cost)
        {
            if( Cost <= m_CostCheck)
                Debug.Log("ConcreteHandler1.核準");
            else
                base.HandleRequest(Cost);
        }
    }

    // 處理所負責的訊息2
    public class ConcreteHandler2 : Handler
    {
        private int m_CostCheck = 20;
        
        public ConcreteHandler2( Handler theNextHandler ) : base( theNextHandler )
        {}
        
        public override void HandleRequest(int Cost)
        {
            if( Cost <= m_CostCheck)
                Debug.Log("ConcreteHandler2.核準");
            else
                base.HandleRequest(Cost);
        }
    }

    // 處理所負責的訊息3
    public class ConcreteHandler3 : Handler
    {           
        public ConcreteHandler3( Handler theNextHandler ) : base( theNextHandler )
        {}  
        public override void HandleRequest(int Cost)
        {
            Debug.Log("ConcreteHandler3.核準");
        }
    }

}

           

using UnityEngine;
using System.Collections;
using DesignPattern_ChainofResponsibility;

public class ChainofResponsibilityTest : MonoBehaviour {

    // Use this for initialization
    void Start () {
        UnitTest();
    }
    
    // 
    void UnitTest () {

        // 建立Cost驗証的連接方式
        ConcreteHandler3 theHandle3 = new ConcreteHandler3(null);
        ConcreteHandler2 theHandle2 = new ConcreteHandler2(theHandle3);
        ConcreteHandler1 theHandle1 = new ConcreteHandler1(theHandle2);

        // 確認
        theHandle1.HandleRequest(10);
        theHandle1.HandleRequest(15);
        theHandle1.HandleRequest(20);
        theHandle1.HandleRequest(30);
        theHandle1.HandleRequest(100);

    
    }
}