C#中抽象工厂设计模式的真实示例

Question

在阅读了许多关于 C# 中抽象工厂设计模式的帖子后，我正在写这个问题。我真的无法从所有这些帖子提供的示例中理解真实世界的用例。我所能看到的只是汽车/电脑/电话等的一些基本示例。我知道它们对于提供简单的解释很重要。但我真的无法将它映射到任何真实世界，因为如果我真的遵循这样的例子，当我想要引入新对象时，我的代码将每隔一周更改一次。

下面是它的示例代码

namespace ClassLibrary1
{

    public interface AbstractProductA { }
    public class ProductA1 : AbstractProductA { }
    public class ProductA2 : AbstractProductA { }


    public interface AbstractProductB { }
    public class ProductB1 : AbstractProductB { }
    public class ProductB2 : AbstractProductB { }


    public interface AbstractFactory
    {
        AbstractProductA CreateProductA();
        AbstractProductB CreateProductB();
    }


    public class ConcreteFactoryA : AbstractFactory
    {
        public AbstractProductA CreateProductA()
        {
            return new ProductA1();
        }

        public AbstractProductB CreateProductB()
        {
            return new ProductB1();
        }
    }

    public class ConcreteFactoryB : AbstractFactory
    {
        public AbstractProductA CreateProductA()
        {
            return new ProductA2();
        }

        public AbstractProductB CreateProductB()
        {
            return new ProductB2();
        }
    }

    public class Client
    {
        private AbstractProductA _productA;
        private AbstractProductB _productB;

        public Client(AbstractFactory factory)
        {
            _productA = factory.CreateProductA();
            _productB = factory.CreateProductB();
        }
    }

}

现在，如何理解它。我可以理解它是如何工作的，但它看起来很幼稚。有一件事是，教程网站上的每个人都选择的示例可能不是正确的示例。

另外，它真正给我带来了什么好处。我可以使用接口以通常的非抽象工厂方式来完成它，整个事情仍然可以正常工作（设计方面）。

详细的例子说明是我要找的

Answer 1

这里我根据我很久以前在我的项目中实现的一个简单的例子向你演示。

public interface IBluetoothCommFactory { }

public interface IWifiCommFactory { }

/// <summary>
/// This is our base factory
/// </summary>
public interface ICommunicationBaseFactory
{
    IBluetoothCommFactory InitializeBluetoothCommunication();
    IWifiCommFactory InitializeWiFiCommnucation();
}

public class BluetoothCommunication : IBluetoothCommFactory
{
    public BluetoothCommunication()
    {
        // Implement some init logic here...
        Console.WriteLine("Bluetooth Communication was initialized");
     }
}

public class WiFiCommunication : IWifiCommFactory
{
    public WiFiCommunication()
    {
        // Implement some init logic here...
        Console.WriteLine("WIFI (generic) Communication was initialized");
    }
}

以上是“通用”BluetoothCommunication 和“通用”WiFiCommunication 的基本实现。假设我们要制作一个名为 ProductPrototypeONE 的产品，它使用这些通用通信类型。

public class ProductPrototypeONE : ICommunicationBaseFactory
{
    public IBluetoothCommFactory InitializeBluetoothCommunication()
    {
        return new BluetoothCommunication();
    }

    public IWifiCommFactory InitializeWiFiCommnucation()
    {
        return new WiFiCommunication();
    }
}

然后在我们的客户端代码中：

ICommunicationBaseFactory baseFactory = new ProductPrototypeONE();
baseFactory.InitializeBluetoothCommunication();
baseFactory.InitializeWiFiCommnucation();

/* CONSOLE OUTPUT */  
Bluetooth Communication was initialized
WIFI (generic) Communication was initialized

接下来，我们要添加另一个要求来创建具有蓝牙低功耗类型和一些特定 WiFi 类型的产品。然后，使用我们创建的同一个工厂，我们可以继续实现这些：

public class BluetoothLowEnergyCommunication : IBluetoothCommFactory
{
    public BluetoothLowEnergyCommunication()
    {
        // Implement some init logic here...
        Console.WriteLine("Bluetooth Low Energy Communication was initialized");
    }
}

public class WiFiLowBandCommunication : IWifiCommFactory
{
    public WiFiLowBandCommunication()
    {
        // Implement some init logic here...
        Console.WriteLine("WIFI Low Band Communication was initialized");
    }
}

public class WifiHighBandCommunication : IWifiCommFactory
{
    public WifiHighBandCommunication()
    {
        // Implement some init logic here...
        Console.WriteLine("WIFI High Band Communication was initialized");
    }
}

然后我们创建 ProductPrototypeTWO 作为一个具体的类：

public enum BluetoothType
{
    CLASSIC_TYPE,
    BLE_TYPE
}

public enum WiFiType
{
    LOW_BAND,
    HIGH_BAND
}

public class ProductPrototypeTWO : ICommunicationBaseFactory
{
    private BluetoothType _bluetoothType;
    private WiFiType _wifiType;

    public ProductPrototypeTWO(BluetoothType bluetoothType, WiFiType wifiType)
    {
        _bluetoothType = bluetoothType;
        _wifiType = wifiType;
    }

    public IBluetoothCommFactory InitializeBluetoothCommunication()
    {
        switch (_bluetoothType)
        {
            case BluetoothType.CLASSIC_TYPE:
                return new BluetoothCommunication();
            case BluetoothType.BLE_TYPE:
                return new BluetoothLowEnergyCommunication();
            default:
                throw new NotSupportedException("Unknown Bluetooth type");
        }
    }

    public IWifiCommFactory InitializeWiFiCommnucation()
    {
        switch (_wifiType)
        {
            case WiFiType.LOW_BAND:
                return new WiFiLowBandCommunication();
            case WiFiType.HIGH_BAND:
                return new WifiHighBandCommunication();
            default:
                throw new NotSupportedException("Unknown WIFI type");
        }
    }
}

最后是客户端代码：

ICommunicationBaseFactory baseFactory = new ProductPrototypeONE();
baseFactory.InitializeBluetoothCommunication();
baseFactory.InitializeWiFiCommnucation();

baseFactory = new ProductPrototypeTWO(BluetoothType.BLE_TYPE, WiFiType.HIGH_BAND);
baseFactory.InitializeBluetoothCommunication();
baseFactory.InitializeWiFiCommnucation();

这是您在输出中的内容：

Bluetooth Communication was initialized
WIFI (generic) Communication was initialized
Bluetooth Low Energy Communication was initialized
WIFI High Band Communication was initialized