C#設計模式之建造者設計模式（Builder）(3)

五、建造者模式的實現：

下面的程序代碼演示了Shop對象使用VehicleBuilders來建造不同的交通工具。該例子使用了Builder模式順序建造交通工具的不同部分。

// Builder pattern -- Real World example　
using System;
using System.Collections;
// "Director"
class Shop
{
　// Methods
　public void Construct( VehicleBuilder vehicleBuilder )
　{
　　vehicleBuilder.BuildFrame();
　　vehicleBuilder.BuildEngine();
　　vehicleBuilder.BuildWheels();
　　vehicleBuilder.BuildDoors();
　}
}
// "Builder"
abstract class VehicleBuilder
{
　// FIElds
　protected Vehicle vehicle;
　// PropertIEs
　public Vehicle Vehicle
　{
　　get{ return vehicle; }
　}
　// Methods
　abstract public void BuildFrame();
　abstract public void BuildEngine();
　abstract public void BuildWheels();
　abstract public void BuildDoors();
}
// "ConcreteBuilder1"
class MotorCycleBuilder : VehicleBuilder
{
　// Methods
　override public void BuildFrame()
　{
　　vehicle = new Vehicle( "MotorCycle" );
　　vehicle[ "frame" ] = "MotorCycle Frame";
　}
　override public void BuildEngine()
　{
　　vehicle[ "engine" ] = "500 cc";
　}
　override public void BuildWheels()
　{
　　vehicle[ "wheels" ] = "2";
　}
　override public void BuildDoors()
　{
　　vehicle[ "doors" ] = "0";
　}
}
// "ConcreteBuilder2"
class CarBuilder : VehicleBuilder
{
　// Methods
　override public void BuildFrame()
　{
　　vehicle = new Vehicle( "Car" );
　　vehicle[ "frame" ] = "Car Frame";
　}
　override public void BuildEngine()
　{
　　vehicle[ "engine" ] = "2500 cc";
　}
　override public void BuildWheels()
　{
　　vehicle[ "wheels" ] = "4";
　}
　override public void BuildDoors()
　{
　　vehicle[ "doors" ] = "4";
　}
}
// "ConcreteBuilder3"
class ScooterBuilder : VehicleBuilder
{
　// Methods
　override public void BuildFrame()
　{
　　vehicle = new Vehicle( "Scooter" );
　　vehicle[ "frame" ] = "Scooter Frame";
　}
　override public void BuildEngine()
　{
　　vehicle[ "engine" ] = "none";
　}
　override public void BuildWheels()
　{
　　vehicle[ "wheels" ] = "2";
　}
　override public void BuildDoors()
　{
　　vehicle[ "doors" ] = "0";
　}
}
// "Product"
class Vehicle
{
　// FIElds
　private string type;
　private Hashtable parts = new Hashtable();
　// Constructors
　public Vehicle( string type )
　{
　　this.type = type;
　}
　// Indexers
　public object this[ string key ]
　{
　　get{ return parts[ key ]; }
　　set{ parts[ key ] = value; }
　}
　// Methods
　public void Show()
　{
　　Console.WriteLine( " ---------------------------");
　　Console.WriteLine( "Vehicle Type: "+ type );
　　Console.WriteLine( " Frame : " + parts[ "frame" ] );
　　Console.WriteLine( " Engine : "+ parts[ "engine"] );
　　Console.WriteLine( " #Wheels: "+ parts[ "wheels"] );
　　Console.WriteLine( " #Doors : "+ parts[ "doors" ] );
　}
}
/**//// <summary>
/// BuilderApp test
/// </summary>
public class BuilderApp
{
　public static void Main( string[] args )
　{
　　// Create shop and vehicle builders
　　Shop shop = new Shop();
　　VehicleBuilder b1 = new ScooterBuilder();
　　VehicleBuilder b2 = new CarBuilder();
　　VehicleBuilder b3 = new MotorCycleBuilder();
　　// Construct and display vehicles
　　shop.Construct( b1 );
　　b1.Vehicle.Show();
　　shop.Construct( b2 );
　　b2.Vehicle.Show();
　　shop.Construct( b3 );
　　b3.Vehicle.Show();
　}
}