The classes and objects participating in this pattern are:
This structural code demonstrates the Prototype pattern in which new objects are created by copying pre-existing objects (prototypes) of the same class.
using System;
namespace DoFactory.GangOfFour.Prototype.Structural
{
/// <summary>
/// MainApp startup class for Structural
/// Prototype Design Pattern.
/// </summary>
class MainApp
{
/// <summary>
/// Entry point into console application.
/// </summary>
static void Main()
{
// Create two instances and clone each
ConcretePrototype1 p1 = new ConcretePrototype1("I");
ConcretePrototype1 c1 = (ConcretePrototype1)p1.Clone();
Console.WriteLine("Cloned: {0}", c1.Id);
ConcretePrototype2 p2 = new ConcretePrototype2("II");
ConcretePrototype2 c2 = (ConcretePrototype2)p2.Clone();
Console.WriteLine("Cloned: {0}", c2.Id);
// Wait for user
Console.ReadKey();
}
}
/// <summary>
/// The 'Prototype' abstract class
/// </summary>
abstract class Prototype
{
private string _id;
// Constructor
public Prototype(string id)
{
this._id = id;
}
// Gets id
public string Id
{
get { return _id; }
}
public abstract Prototype Clone();
}
/// <summary>
/// A 'ConcretePrototype' class
/// </summary>
class ConcretePrototype1 : Prototype
{
// Constructor
public ConcretePrototype1(string id)
: base(id)
{
}
// Returns a shallow copy
public override Prototype Clone()
{
return (Prototype)this.MemberwiseClone();
}
}
/// <summary>
/// A 'ConcretePrototype' class
/// </summary>
class ConcretePrototype2 : Prototype
{
// Constructor
public ConcretePrototype2(string id)
: base(id)
{
}
// Returns a shallow copy
public override Prototype Clone()
{
return (Prototype)this.MemberwiseClone();
}
}
}
This real-world code demonstrates the Prototype pattern in which new Color objects are created by copying pre-existing, user-defined Colors of the same type.
using System;
using System.Collections.Generic;
namespace DoFactory.GangOfFour.Prototype.RealWorld
{
/// <summary>
/// MainApp startup class for Real-World
/// Prototype Design Pattern.
/// </summary>
class MainApp
{
/// <summary>
/// Entry point into console application.
/// </summary>
static void Main()
{
ColorManager colormanager = new ColorManager();
// Initialize with standard colors
colormanager["red"] = new Color(255, 0, 0);
colormanager["green"] = new Color(0, 255, 0);
colormanager["blue"] = new Color(0, 0, 255);
// User adds personalized colors
colormanager["angry"] = new Color(255, 54, 0);
colormanager["peace"] = new Color(128, 211, 128);
colormanager["flame"] = new Color(211, 34, 20);
// User clones selected colors
Color color1 = colormanager["red"].Clone() as Color;
Color color2 = colormanager["peace"].Clone() as Color;
Color color3 = colormanager["flame"].Clone() as Color;
// Wait for user
Console.ReadKey();
}
}
/// <summary>
/// The 'Prototype' abstract class
/// </summary>
abstract class ColorPrototype
{
public abstract ColorPrototype Clone();
}
/// <summary>
/// The 'ConcretePrototype' class
/// </summary>
class Color : ColorPrototype
{
private int _red;
private int _green;
private int _blue;
// Constructor
public Color(int red, int green, int blue)
{
this._red = red;
this._green = green;
this._blue = blue;
}
// Create a shallow copy
public override ColorPrototype Clone()
{
Console.WriteLine(
"Cloning color RGB: {0,3},{1,3},{2,3}",
_red, _green, _blue);
return this.MemberwiseClone() as ColorPrototype;
}
}
/// <summary>
/// Prototype manager
/// </summary>
class ColorManager
{
private Dictionary<string, ColorPrototype> _colors =
new Dictionary<string, ColorPrototype>();
// Indexer
public ColorPrototype this[string key]
{
get { return _colors[key]; }
set { _colors.Add(key, value); }
}
}
}
The .NET optimized code demonstrates the
same real-world situation as above but uses modern, built-in .NET features,
such as, generics, reflection, object initializers, automatic properties, etc.
You can find an example on our Singleton pattern page.
All other patterns (and much more) are available in our .NET Design Pattern Framework 4.5.
Not only does the .NET Design Pattern Framework 4.5 cover GOF and Enterprise patterns, it also includes .NET pattern architectures that reduce the code you need to write by up to 75%. This unique package will change your .NET lifestyle -- for only $79. Here's what is included:
