责任链模式

经理和高管可以响应采购请求或将其移交给上级。
每个位置都可以有自己的一套规则，他们可以批准这些订单。

• 首先有一个领导类专门负责处理这些请求
• 之后根据权限分别对子类进行处理
• 在调用的时候会根据处理类的权限进行处理，如果权限不足就传递给下一级别

public class ChainOfResponsibility:MonoBehaviour{
	void Start{
		Approver llw = new Director();
		Approver al = new ViceScident();
		Approver mcl = new Prescident();
		llw.SetSuccessor(al);
		al.SetSuccessor(mcl);
		Purchase purchase = new Purchase(900.00,90,"Assets");
		llw.ProcessRequest(purchase);
		purchase = new Purchase(4001.21,29,"");
		llw.ProcessRequest(purchase);
		purchase = new Purchase(100021,890,"");
	}
	/// 负责处理请求的基类（领导）
	public class Approver{
		protected Approver successor; // 上级
		public void SetSuccessor(Approver successor){
			this.successor = successor;
		}
		public abstract  void ProcessRequest(Purchase purchase);
	}
	public class Purchase{
		private float m_amount; //金额
		private int m_number; //采购数量
		private string m_purpose; // 目的
		// 赋值
		public Purchase(float m_amount,int m_number,string m_purpose){
			this.m_purpose = m_purpose;
			this.m_amount = m_amount;
			this.m_number = m_number; 
		}
		public float Amount
		{
			get{return m_amount;}
			set{m_amount = value;}
		}
		public int Number
		{
			get{return m_number;}
			set{m_number = value;}
		}
		public string Purpose
		{
			get{return m_purpose;}
			set{m_purpose = value;}
		}
	}
	public class Director:Approver{
		if (purchase.Amount < 10000.0)
            {
                Debug.Log(this.GetType().Name+" approved request# "+purchase.Number);
            }
            else if (successor != null)
            {
                successor.ProcessRequest(purchase);
            }
	}
	public calss Prescident:Approver{
		if (purchase.Amount < 100000.0)
            {
                Debug.Log(this.GetType().Name+" approved request# "+purchase.Number);
            }
            else 
            {
                Debug.Log("Request# "+purchase.Number+ "requires an executive meeting!");
            }
	}
	public class VivePrescident:Approver{
		public override void ProcessRequest(Purchase purchase){
			if (purchase.Amount < 50000.0)
            {
                Debug.Log(this.GetType().Name+" approved request# "+purchase.Number);
            }
            else if (successor != null)
            {
                successor.ProcessRequest(purchase);
            }
		}
	}
}

根据提供的计算类型进行计算

public class ChainOfResponsibility2 : MonoBehaviour{
	void Start(){
		IChainOfCalc calc1 = new AddNumbers();
		IChainOfCalc calc2 = new SubstractNumbers();
		IChainOfCalc calc3 = new DivideNumbers();
		IChainOfCalc calc4 = new MultiplyNumbers();

		calc1.SetNextChain(calc2);
		calc2.SetNextChain(calc3);
		calc3.SetNextChain(calc4);
		Number myNumbers = new Number(3, 5, CalculationType.Add);
		calc1.Calculate(myNumbers);

		// another example:
		Number myOtherNumbers = new Number(6, 2, CalculationType.Multiply);
		calc1.Calculate(myOtherNumbers);

		// or pass it to some chain object inbetween which will not work in this case:
		Number myLastNumbers = new Number(12, 3, CalculationType.Subtract);
		calc3.Calculate(myLastNumbers);		
		
	}
	// 计算的类型
	public enum CalculationType
	{
		Add,
		Subtract,
		Divide,
		Multiply
	};
	
	public interface IChainOfCalc{
		void SetNextChain(IChainOfCalc nextChain);
		void Calculate(Number number);
	}
	public class Number{
		public int Num1{get; protected set;}
		public int Num2{get; protected set;}
		public CalculationType CalcType{get; protected set;}
		public Number(int num1, int num2 , CalculationType calc){
			this.Num1 = num1;
			this.Num2 = num2;
			this.CalcType = calc;
		}
	}
	
	public class AddNumber : IChainOfCalc{
		protected IChainOfCalc nextChain; 
		public void  SetNextChain(IChainOfCalc nextChain){
			this.nextChain = nextChain;
		}
		public void Calculate(Number request){
			if(request.CalcType == CalculationType.Add)
			{
				Debug.Log("Adding: " + request.number1 + " + " + request.number2 + " = " + (request.number1 + request.number2).ToString());
			}
			else if(nextInChain != null)
				nextInChain.Calculate(request);
			else
				Debug.Log ("Handling of request failed: " + request.calculationWanted);
		}
	}
	public class SubtractNumber : IChainOfCalc
	{
		protected IChainOfCalc nextInChain;

		public void SetNextChain(IChainOfCalc nextChain)
		{
			this.nextInChain = nextChain;
		}

		public void Calculate(Number request)
		{
			if(request.CalcType == CalculationType.Subtract)
			{
				Debug.Log("Substracting: " + request.number1 + " - " + request.number2 + " = " + (request.number1 - request.number2).ToString());
			}
			else if(nextInChain != null)
				nextInChain.Calculate(request);
			else
				Debug.Log ("Handling of request failed: " + request.calculationWanted);
		}
	}
	public class DivideNumber : IChainOfCalc
	{
		protected IChainOfCalc nextInChain;
		
		public void SetNextChain(IChainOfCalc nextChain)
		{
			this.nextInChain = nextChain;
		}
		
		public void Calculate(Number request)
		{
			if(request.CalcType == CalculationType.Divide)
			{
				Debug.Log("Dividing: " + request.number1 + " / " + request.number2 + " = " + (request.number1 / request.number2).ToString());
			}
			else if(nextInChain != null)
				nextInChain.Calculate(request);
			else
				Debug.Log ("Handling of request failed: " + request.calculationWanted);
		}
	}
	public class MultiplyNumber : IChainOfCalc
	{
		protected IChainOfCalc nextInChain;
		
		public void SetNextChain(IChainOfCalc nextChain)
		{
			this.nextInChain = nextChain;
		}
		
		public void Calculate(Number request)
		{
			if(request.CalcType == CalculationType.Multiply)
			{
				Debug.Log("Multiplying: " + request.number1 + " * " + request.number2 + " = " + (request.number1 * request.number2).ToString());
			}
			else if(nextInChain != null)
				nextInChain.Calculate(request);
			else
				Debug.Log ("Handling of request failed: " + request.calculationWanted);
		}
	}
}

最后根据上述思路可以在Unity写出一个关卡选择器等等