mementorealworld.cs

使用C#程序将23个常用设计模式进行列表显示

using System;
using System.Windows.Forms;
using System.Text;

//备忘录模式(Memento)
//意图
//    在不破坏封装性的前提下，捕获一个对象的内部状态，并在该对象之外保存这个状态。这样以后就可将该对象恢复到原先保存的状态。
//适用性
//    1.必须保存一个对象在某一个时刻的(部分)状态, 这样以后需要时它才能恢复到先前的状态。
//    2.如果一个用接口来让其它对象直接得到这些状态，将会暴露对象的实现细节并破坏对象的封装性。

namespace DesignPattern.MementoRealWorld
{
    class MementoRealWorld : AbstractPattern
    {
        public static void Run(TextBox tbInfo)
        {
            s_tbInfo = tbInfo;
            s_tbInfo.Text = "";

            SalesProspect s = new SalesProspect(); 
            s.Name = "Noel van Halen"; 
            s.Phone = "[phone]";
            s.Budget = 25000.0;
            
            // Store internal state 
            ProspectMemory m = new ProspectMemory(); 
            m.Memento = s.SaveMemento(); 
            
            // Continue changing originator 
            s.Name = "Leo Welch"; 
            s.Phone = "[phone]"; 
            s.Budget = 1000000.0; 
            
            // Restore saved state 
            s.RestoreMemento(m.Memento); 

            // Wait for user 
            //Console.Read();
        }
    }
    // "Originator" 
    class SalesProspect 
    {
        private string name; 
        private string phone; 
        private double budget;
        
        // Properties 
        public string Name 
        {
            get{ return name; } 
            set 
            {
                name = value; 
                DesignPattern.FormMain.OutputInfo("Name: " + name); 
            }
        }
        public string Phone 
        {
            get{ return phone; } 
            set 
            { 
                phone = value; 
                DesignPattern.FormMain.OutputInfo("Phone: " + phone); 
            }
        }
        public double Budget 
        {
            get{ return budget; } 
            set
            {
                budget = value; 
                DesignPattern.FormMain.OutputInfo("Budget: " + budget); 
            }
        }
        public Memento SaveMemento()
        {
            DesignPattern.FormMain.OutputInfo("\nSaving state --\n"); 
            return new Memento(name, phone, budget); 
        }
        
        public void RestoreMemento(Memento memento) 
        {
            DesignPattern.FormMain.OutputInfo("\nRestoring state --\n"); 
            this.Name = memento.Name; 
            this.Phone = memento.Phone; 
            this.Budget = memento.Budget;
        }
    }
 
    // "Memento" 
    class Memento 
    { 
        private string name; 
        private string phone; 
        private double budget; 
        
        // Constructor 
        public Memento(string name, string phone, double budget) 
        {
            this.name = name; 
            this.phone = phone; 
            this.budget = budget; 
        }
        // Properties 
        public string Name 
        {
            get{ return name; } 
            set{ name = value; } 
        }
        public string Phone 
        {
            get{ return phone; } 
            set{ phone = value; } 
        }
        public double Budget 
        { 
            get{ return budget; } 
            set{ budget = value; }
        }
    }
    
    // "Caretaker" 
    class ProspectMemory 
    {
        private Memento memento;
        // Property 
        public Memento Memento 
        {
            set{ memento = value; } 
            get{ return memento; } 
        }
    }
}