步步为营 .NET 代码重构学习笔记 八

一、Introduce Foreign Method(引入外加函数)

动机(Motivation)

在client class 中建立一个函数,并以一个server class实体作为第一引数(argument)。

示例

DateTime newStart = DateTime.Now.AddDays(1);

改为

        public DateTime  NextDate()
        {
            return  DateTime.Now.AddDays(1);
         
        }

二、Introduce Local Extension(引入本地扩展)

动机(Motivation)

建立一个新class,使它包含这些额外函数。让这个扩展品成为source class的subclass(子类)或wrapper(外覆类)。

示例

        protected void Main()
        {
            Computer _computer;
            StringBuilder strCom = new StringBuilder();
            strCom.AppendLine("你的电脑配置如下:");
            strCom.AppendLine("主板是:" + _computer.MainBoard());
            strCom.AppendLine("处理器是:" + _computer.Cpu());
            strCom.AppendLine("显卡是:" + _computer.PhenoType());
            strCom.AppendLine("内存是:" + _computer.Memory());
            strCom.AppendLine("硬盘是:" + _computer.HardDisk());
            strCom.AppendLine("显示器是:" + _computer.Display());
            strCom.AppendLine("己组装完成");
            Console.WriteLine(strCom.ToString);
        }

改为

   protected void Main()
        {
            Console.WriteLine(ShowComputerConfigure());
        }

        public string ShowComputerConfigure()
        {
            Computer _computer;
            StringBuilder strCom = new StringBuilder();
            strCom.AppendLine("你的电脑配置如下:");
            strCom.AppendLine("主板是:" + _computer.MainBoard());
            strCom.AppendLine("处理器是:" + _computer.Cpu());
            strCom.AppendLine("显卡是:" + _computer.PhenoType());
            strCom.AppendLine("内存是:" + _computer.Memory());
            strCom.AppendLine("硬盘是:" + _computer.HardDisk());
            strCom.AppendLine("显示器是:" + _computer.Display());
            strCom.AppendLine("己组装完成");

            return strCom.ToString();
        }

三、Self Encapsulate Field(自封装值域)

动机(Motivation)

为这个值域建立取值/设置函数(getting/setting methods),并且只以这些函数来访问值域。

示例

        public  int _low, _high;
        public bool Includes(int arg)
        {
            return arg >= _low && arg <= _high;
        }

改为

        private int _low, _high;

        public int Low
        {
            get { return _low; }
            set { _low = value; }
        }

        public int High
        {
            get { return _high; }
            set { _high = value; }
        }

        public bool Includes(int arg)
        {
            return arg >= Low && arg <= High;
        }

四、Replace Data Value with Object(以对象取代数据值)

动机(Motivation)

将数据项变成一个对象

示例

    public class Customer
    {
        private string _name;
        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }
    }

改为

    public class Customer
    {
        private string _name;
        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }
        public Customer(string name)
        {
            this._name = name;
        }
    }

引用时

  string name = new Customer("spring yang");

五、Change Value to Referencce(将实值对象改为引用对象)

动机(Motivation)

将value object(实值对象)变成一个reference object(引用对象)

示例

        public void GetCustomers()
        {
            string[] UserName = { new Customer("Spring Yang"), new Customer("Lemon Car"), new Customer("Associated Coffee") };
        }

改为

 private Dictionary<string, Customer> dicUserName = new Dictionary<string, Customer>();

        public void GetCustomers()
        {
            string[] UserName = { dicUserName.TryGetValue("Spring Yang"), dicUserName.TryGetValue("Lemon Car"),
                                    dicUserName.TryGetValue("Associated Coffee") };
        }

        private void LoadCustomers()
        {
            AddCustomer("Spring Yang");
            AddCustomer("Lemon Car");
            AddCustomer("Associated Coffee");
        }

        private void AddCustomer(string name)
        {
            dicUserName.Add(name, new Customer(name));
        }

六、Change Reference to Value(将引用对象改为实值对象)

动机(Motivation)

reference object(引用对象),很小且不可变(immutable),而且不易管理。

示例

 private Dictionary<string, Customer> dicUserName = new Dictionary<string, Customer>();

        public void GetCustomers()
        {
            string[] UserName = { dicUserName.TryGetValue("Spring Yang"), dicUserName.TryGetValue("Lemon Car"),
                                    dicUserName.TryGetValue("Associated Coffee") };
        }

        private void LoadCustomers()
        {
            AddCustomer("Spring Yang");
            AddCustomer("Lemon Car");
            AddCustomer("Associated Coffee");
        }

        private void AddCustomer(string name)
        {
            dicUserName.Add(name, new Customer(name));
        }

改为

        public void GetCustomers()
        {
            string[] UserName = { new Customer("Spring Yang"), new Customer("Lemon Car"), new Customer("Associated Coffee") };
        }

七、Replace Array with Object(以对象取代数组)

动机(Motivation)

以对象替换数组。对于数组中的每个元素,以一个值域表示。

示例

        public void Main()
        {
            string[] UserInfo = new string[3];
            UserInfo[0] = "1";
            UserInfo[1] = "spring yang";
            UserInfo[2] = "IT";
        }

改为

        public void Main()
        {
            User user = new User();
            user.ID = "1";
            user.Name = "spring yang";
            user.Depart = "IT";
        }
posted @ 2011-05-30 00:05  spring yang  阅读(1678)  评论(2编辑  收藏  举报