[读书笔记]大话设计模式 计算器设计

挺明白的计算器设计，写的非常不错。

 

代码

   
     

    
      
    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Linq;

    
      using
    
       System.Text;


    
      namespace
    
       ConsoleApplication1
{
 
    
      public
    
       
    
      class
    
       Operation
 {
 
    
      private
    
       
    
      double
    
       _numberA 
    
      =
    
       
    
      0
    
      ;
 
    
      private
    
       
    
      double
    
       _numberB 
    
      =
    
       
    
      0
    
      ;

 
    
      public
    
       
    
      double
    
       NumberA
 {
 
    
      get
    
      
 {
 
    
      return
    
       _numberA;
 }
 
    
      set
    
      
 {
 _numberA 
    
      =
    
       value;
 }
 }

 
    
      public
    
       
    
      double
    
       NumberB
 {
 
    
      get
    
      
 {
 
    
      return
    
       _numberB;
 }
 
    
      set
    
      
 {
 _numberB 
    
      =
    
       value;
 }
 }

 
    
      public
    
       
    
      virtual
    
       
    
      double
    
       GetResult()
 {
 
    
      double
    
       result 
    
      =
    
       
    
      0
    
      ;
 
    
      return
    
       result;
 }
 }

 
    
      class
    
       OperationAdd : Operation
 {
 
    
      public
    
       
    
      override
    
       
    
      double
    
       GetResult()
 {
 
    
      double
    
       result 
    
      =
    
       
    
      0
    
      ;
 result 
    
      =
    
       NumberA 
    
      +
    
       NumberB;
 
    
      return
    
       result; 
 }
 }

 
    
      public
    
       
    
      class
    
       OperationFactory
 {
 
    
      public
    
       
    
      static
    
       Operation createOperate(
    
      string
    
       operate)
 {
 Operation oper 
    
      =
    
       
    
      null
    
      ;
 
    
      switch
    
       (operate)
 {
 
    
      case
    
       
    
      "
    
      +
    
      "
    
      :
 oper 
    
      =
    
       
    
      new
    
       OperationAdd();
 
    
      break
    
      ;
 
    
      case
    
       
    
      "
    
      -
    
      "
    
      :
 oper 
    
      =
    
       
    
      new
    
       OperationSub();
 
    
      break
    
      ;
 
    
      case
    
       
    
      "
    
      *
    
      "
    
      :
 oper 
    
      =
    
       
    
      new
    
       OperationMul();
 
    
      break
    
      ;
 
    
      case
    
       
    
      "
    
      /
    
      "
    
      :
 oper 
    
      =
    
       
    
      new
    
       OperationDiv();
 
    
      break
    
      ;
 }
 
    
      return
    
       oper;
 }
 }

 
    
      class
    
       OperationSub : Operation
 {
 
    
      public
    
       
    
      override
    
       
    
      double
    
       GetResult()
 {
 
    
      double
    
       result 
    
      =
    
       
    
      0
    
      ;
 result 
    
      =
    
       NumberA 
    
      -
    
       NumberB;
 
    
      return
    
       result;
 }
 }

 
    
      class
    
       OperationMul : Operation
 {
 
    
      public
    
       
    
      override
    
       
    
      double
    
       GetResult()
 {
 
    
      double
    
       result 
    
      =
    
       
    
      0
    
      ;
 result 
    
      =
    
       NumberA 
    
      *
    
       NumberB;
 
    
      return
    
       result;
 }
 }

 
    
      class
    
       OperationDiv : Operation
 {
 
    
      public
    
       
    
      override
    
       
    
      double
    
       GetResult()
 {
 
    
      double
    
       result 
    
      =
    
       
    
      0
    
      ;
 
    
      if
    
       (NumberB 
    
      ==
    
       
    
      0
    
      )
 
    
      throw
    
       
    
      new
    
       Exception(
    
      "
    
      除数不能为0。
    
      "
    
      );
 result 
    
      =
    
       NumberA 
    
      /
    
       NumberB;
 
    
      return
    
       result;
 }
 }


 
    
      class
    
       Program
 {
 
    
      static
    
       
    
      void
    
       Main(
    
      string
    
      [] args)
 {
 Operation oper;
 oper 
    
      =
    
       OperationFactory.createOperate(
    
      "
    
      +
    
      "
    
      );
 oper.NumberA 
    
      =
    
       
    
      1
    
      ;
 oper.NumberB 
    
      =
    
       
    
      2
    
      ;
 
    
      double
    
       result 
    
      =
    
       oper.GetResult();
 Console.WriteLine(result);
 }
 }
}

   
     

public class OperationFactory   
   public static Operation createOperate(string operate)

在OperationFactory里面定义一个静态Operation成员类createOperate, 用string operate 初始化？

 

有点不怎么明白o(╯□╰)o