Design Mode: Prototype

Design Mode: Prototype

1. Class Diagram

Instance class diagram

2. Create a project

..........................................

3. Create a weekly report WeeklyLog: act as the prototype. The Clone () method is used to Clone the prototype object. Attachmentch acts as the member class.

The Attachmentch code is as follows:

Using System;

Namespace PrototypeSample

{

[Serializable]

Class Attachment

{

Private string name;

 

Public string Name

{

Get {return name ;}

Set {name = value ;}

}

 

Public void Download ()

{

Console. WriteLine ("Download Attachment, file name: {0 }. ", Name );

}

}

}

 

4. The WeeklyLog class code is as follows:

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

{

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 ;}

}

/*

// Use the MemberwiseClone () method for shortest cloning

Public WeeklyLog Clone ()

{

Return this. MemberwiseClone () as WeeklyLog;

}

*/

// Achieve deep cloning using serialization

Public WeeklyLog Clone ()

{

WeeklyLog clone = null;

// Serialization

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

BinaryFormatter formatter = new BinaryFormatter ();

Try

{

// Serialize the current object to Temp. dat

Formatter. Serialize (fs, this );

}

Catch (SerializationException e)

{

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

Throw;

}

Finally

{

Fs. Close ();

}

// Deserialization

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

BinaryFormatter formatter1 = new BinaryFormatter ();

Try

{

// Deserialize from stream to object

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

}

Catch (SerializationException e)

{

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

Throw;

}

Finally

{

Fs. Close ();

}

Return clone;

}

}

}

5. Client test class 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_previus.attachment = attachment;

Log_new = log_previus.clone ();

Console. WriteLine ("is the weekly report the same? {0} ", (log_previous = log_new )? "Yes": "no ");

Console. WriteLine ("is the attachment the same? {0} ", (log_previus.attachment = log_new.Attachment )? "Yes": "no ");

Console. Read ();

}

}

}

6. Compile and run the program and output the following results:

 

7. Deep clone solution:

1) Mark weekly WeeklyLog and Attachment class Attachment as Serializable)

[Serializable]

Class WeeklyLog

{

Private Attachment attachment;

......

}

[Serializable]

Class Attachment

{

......

}

// Achieve deep cloning using serialization

Public WeeklyLog Clone ()

{

WeeklyLog clone = null;

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

BinaryFormatter formatter = new BinaryFormatter ();

Try

{

Formatter. Serialize (fs, this); // serialization

}

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); // deserialization

}

Catch (SerializationException e)

{

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

Throw;

}

Finally

{

Fs1.Close ();

}

Return clone;

}