生成器模式
将复杂对象的构造与其表示分开,以便相同的构造过程可以创建不同的表示,并提供对对象组装的高级控制。
在此示例中演示了构建器模式,其中不同的车辆以逐步的方式组装。车间使用 VehicleBuilders 以一系列连续步骤构建各种车辆。
using System;
using System.Collections.Generic;
namespace GangOfFour.Builder
{
/// <summary>
/// MainApp startup class for Real-World
/// Builder Design Pattern.
/// </summary>
public class MainApp
{
/// <summary>
/// Entry point into console application.
/// </summary>
public static void Main()
{
VehicleBuilder builder;
// Create shop with vehicle builders
Shop shop = new Shop();
// Construct and display vehicles
builder = new ScooterBuilder();
shop.Construct(builder);
builder.Vehicle.Show();
builder = new CarBuilder();
shop.Construct(builder);
builder.Vehicle.Show();
builder = new MotorCycleBuilder();
shop.Construct(builder);
builder.Vehicle.Show();
// Wait for user
Console.ReadKey();
}
}
/// <summary>
/// The 'Director' class
/// </summary>
class Shop
{
// Builder uses a complex series of steps
public void Construct(VehicleBuilder vehicleBuilder)
{
vehicleBuilder.BuildFrame();
vehicleBuilder.BuildEngine();
vehicleBuilder.BuildWheels();
vehicleBuilder.BuildDoors();
}
}
/// <summary>
/// The 'Builder' abstract class
/// </summary>
abstract class VehicleBuilder
{
protected Vehicle vehicle;
// Gets vehicle instance
public Vehicle Vehicle
{
get { return vehicle; }
}
// Abstract build methods
public abstract void BuildFrame();
public abstract void BuildEngine();
public abstract void BuildWheels();
public abstract void BuildDoors();
}
/// <summary>
/// The 'ConcreteBuilder1' class
/// </summary>
class MotorCycleBuilder : VehicleBuilder
{
public MotorCycleBuilder()
{
vehicle = new Vehicle("MotorCycle");
}
public override void BuildFrame()
{
vehicle["frame"] = "MotorCycle Frame";
}
public override void BuildEngine()
{
vehicle["engine"] = "500 cc";
}
public override void BuildWheels()
{
vehicle["wheels"] = "2";
}
public override void BuildDoors()
{
vehicle["doors"] = "0";
}
}
/// <summary>
/// The 'ConcreteBuilder2' class
/// </summary>
class CarBuilder : VehicleBuilder
{
public CarBuilder()
{
vehicle = new Vehicle("Car");
}
public override void BuildFrame()
{
vehicle["frame"] = "Car Frame";
}
public override void BuildEngine()
{
vehicle["engine"] = "2500 cc";
}
public override void BuildWheels()
{
vehicle["wheels"] = "4";
}
public override void BuildDoors()
{
vehicle["doors"] = "4";
}
}
/// <summary>
/// The 'ConcreteBuilder3' class
/// </summary>
class ScooterBuilder : VehicleBuilder
{
public ScooterBuilder()
{
vehicle = new Vehicle("Scooter");
}
public override void BuildFrame()
{
vehicle["frame"] = "Scooter Frame";
}
public override void BuildEngine()
{
vehicle["engine"] = "50 cc";
}
public override void BuildWheels()
{
vehicle["wheels"] = "2";
}
public override void BuildDoors()
{
vehicle["doors"] = "0";
}
}
/// <summary>
/// The 'Product' class
/// </summary>
class Vehicle
{
private string _vehicleType;
private Dictionary<string,string> _parts =
new Dictionary<string,string>();
// Constructor
public Vehicle(string vehicleType)
{
this._vehicleType = vehicleType;
}
// Indexer
public string this[string key]
{
get { return _parts[key]; }
set { _parts[key] = value; }
}
public void Show()
{
Console.WriteLine("\n---------------------------");
Console.WriteLine("Vehicle Type: {0}", _vehicleType);
Console.WriteLine(" Frame : {0}", _parts["frame"]);
Console.WriteLine(" Engine : {0}", _parts["engine"]);
Console.WriteLine(" #Wheels: {0}", _parts["wheels"]);
Console.WriteLine(" #Doors : {0}", _parts["doors"]);
}
}
}
输出
车型:踏板车车架:踏板车车架
发动机:无
#Wheels:2
#门:0
车型:
车架:车架
发动机:2500 cc
#Wheels:4
#门:4
车型:MotorCycle
车架:MotorCycle 车架
发动机:500 cc
#Wheels:2
#门:0