设计模式之原型模式

Posted Jonny

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1、类图

实例类图

2、创建项目

……………………………………

3、 新建周报类WeeklyLog:充当原型角色,Clone()方法为克隆方法,用于实现原型对象的克隆,Attachmentch充当成员类。

Attachmentch代码如下:

using System;

namespace PrototypeSample

{

    [Serializable]

    class Attachment

    {

        private string name;

 

        public string Name

        {

            get { return name; }

            set { name = value; }

        }

 

        public void Download()

        {

            Console.WriteLine("下载附件,文件名为{0}。",name);

        }

    }

}

 

4、WeeklyLog类代码如下:

using System;

using System.IO;

using System.Collections;

using System.Runtime.Serialization.Formatters.Binary;

using System.Runtime.Serialization;

namespace PrototypeSample

{

    [Serializable]

    class WeeklyLog

    {

        private Attachment attachment;

        private string name;

        private string date;     

        private string content;

 

        public Attachment Attachment

        {

            get { return attachment; }

            set { attachment = value; }

        }

        public string Name

        {

            get { return name; }

            set { name = value; }

        }

        public string Date

        {

            get { return date; }

            set { date = value; }

        }

        public string Content

        {

            get { return content; }

            set { content = value; }

        }

        /*

        //使用MemberwiseClone()方法实现浅克隆

        public WeeklyLog Clone()

        {

            return this.MemberwiseClone() as WeeklyLog;

        }

         */

        //使用序列化方式实现深克隆

        public WeeklyLog Clone()

        {

            WeeklyLog clone = null;

            //序列化

            FileStream fs = new FileStream("Temp.dat", FileMode.Create);

            BinaryFormatter formatter = new BinaryFormatter();

            try

            {

                //对当前对象执行序列化操作到Temp.dat

                formatter.Serialize(fs, this);

            }

            catch (SerializationException e)

            {

                Console.WriteLine("Failed to serialize. Reason: " + e.Message);

                throw;

            }

            finally

            {

                fs.Close();

            }

            //反序列化

            FileStream fs1 = new FileStream("Temp.dat", FileMode.Open);

            BinaryFormatter formatter1 = new BinaryFormatter();

            try

            {

                //从流中反序列化到对象

                clone = (WeeklyLog)formatter1.Deserialize(fs1);

            }

            catch (SerializationException e)

            {

                Console.WriteLine("Failed to deserialize. Reason: " + e.Message);

                throw;

            }

            finally

            {

                fs.Close();

            }

            return clone;

        }

    }

}

5、 客户端测试类Program:

using System;

namespace PrototypeSample

{

    class Program

    {

        static void Main(string[] args)

        {

            /*

            ConcretePrototypeB prototype, copy;

            prototype = new ConcretePrototypeB();

            //prototype.Attr = "Sunny";

            copy = (ConcretePrototypeB)prototype.Clone();

            //copy.Attr = "Tom";

            Console.WriteLine(prototype == copy);

            //Console.WriteLine(prototype.GetType() == copy.GetType());

            Console.WriteLine(prototype.Member == copy.Member);

            Console.Read();

            */

 

            WeeklyLog log_previous, log_new;

            log_previous = new WeeklyLog();

            Attachment attachment = new Attachment();

            log_previous.Attachment = attachment;

            log_new = log_previous.Clone();

            Console.WriteLine("周报是否相同?{0}",(log_previous == log_new)?"是":"否");

            Console.WriteLine("附件是否相同?{0}",(log_previous.Attachment == log_new.Attachment)?"是":"否");

           Console.Read();

        }

    }

}

6、 编译及运行程序,输出如下结果:

 

7、 深克隆解决方案:

1) 将周报类WeeklyLog和附件类Attachment标记为可序列化(Serializable)

[Serializable]

class WeeklyLog

{

    private Attachment attachment;

……

}

[Serializable]

class Attachment

{

……

}

//使用序列化方式实现深克隆

public WeeklyLog Clone()

{

    WeeklyLog clone = null;

    FileStream fs = new FileStream("Temp.dat", FileMode.Create);

    BinaryFormatter formatter = new BinaryFormatter();

    try

    {

        formatter.Serialize(fs, this);  //序列化

    }

    catch (SerializationException e)

    {

        Console.WriteLine("Failed to serialize. Reason: " + e.Message);

        throw;

    }

    finally

    {

        fs.Close();

    }

    FileStream fs1 = new FileStream("Temp.dat", FileMode.Open);

    BinaryFormatter formatter1 = new BinaryFormatter();

    try

    {

        clone = (WeeklyLog)formatter1.Deserialize(fs1);  //反序列化

    }

    catch (SerializationException e)

    {

        Console.WriteLine("Failed to deserialize. Reason: " + e.Message);

        throw;

    }

    finally

    {

        fs1.Close();

    }

        return clone;

 

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