Spring SALE

C# 外观模式讲解和代码示例

外观是一种结构型设计模式 能为复杂系统 程序库或框架提供一个简单 但有限 的接口

尽管外观模式降低了程序的整体复杂度 但它同时也有助于将不需要的依赖移动到同一个位置



使用示例 使用 C# 开发的程序中会经常使用外观模式 它在与复杂程序库和 API 协作时特别有用

识别方法 外观可以通过使用简单接口 但将绝大部分工作委派给其他类的类来识别 通常情况下 外观管理其所使用的对象的完整生命周期



  • 它由哪些类组成
  • 这些类扮演了哪些角色
  • 模式中的各个元素会以何种方式相互关联

Program.cs: 概念示例

using System;

namespace RefactoringGuru.DesignPatterns.Facade.Conceptual
    // The Facade class provides a simple interface to the complex logic of one
    // or several subsystems. The Facade delegates the client requests to the
    // appropriate objects within the subsystem. The Facade is also responsible
    // for managing their lifecycle. All of this shields the client from the
    // undesired complexity of the subsystem.
    public class Facade
        protected Subsystem1 _subsystem1;
        protected Subsystem2 _subsystem2;

        public Facade(Subsystem1 subsystem1, Subsystem2 subsystem2)
            this._subsystem1 = subsystem1;
            this._subsystem2 = subsystem2;
        // The Facade's methods are convenient shortcuts to the sophisticated
        // functionality of the subsystems. However, clients get only to a
        // fraction of a subsystem's capabilities.
        public string Operation()
            string result = "Facade initializes subsystems:\n";
            result += this._subsystem1.operation1();
            result += this._subsystem2.operation1();
            result += "Facade orders subsystems to perform the action:\n";
            result += this._subsystem1.operationN();
            result += this._subsystem2.operationZ();
            return result;
    // The Subsystem can accept requests either from the facade or client
    // directly. In any case, to the Subsystem, the Facade is yet another
    // client, and it's not a part of the Subsystem.
    public class Subsystem1
        public string operation1()
            return "Subsystem1: Ready!\n";

        public string operationN()
            return "Subsystem1: Go!\n";
    // Some facades can work with multiple subsystems at the same time.
    public class Subsystem2
        public string operation1()
            return "Subsystem2: Get ready!\n";

        public string operationZ()
            return "Subsystem2: Fire!\n";

    class Client
        // The client code works with complex subsystems through a simple
        // interface provided by the Facade. When a facade manages the lifecycle
        // of the subsystem, the client might not even know about the existence
        // of the subsystem. This approach lets you keep the complexity under
        // control.
        public static void ClientCode(Facade facade)
    class Program
        static void Main(string[] args)
            // The client code may have some of the subsystem's objects already
            // created. In this case, it might be worthwhile to initialize the
            // Facade with these objects instead of letting the Facade create
            // new instances.
            Subsystem1 subsystem1 = new Subsystem1();
            Subsystem2 subsystem2 = new Subsystem2();
            Facade facade = new Facade(subsystem1, subsystem2);

Output.txt: 执行结果

Facade initializes subsystems:
Subsystem1: Ready!
Subsystem2: Get ready!
Facade orders subsystems to perform the action:
Subsystem1: Go!
Subsystem2: Fire!


C++ 外观模式讲解和代码示例 Go 外观模式讲解和代码示例 Java 外观模式讲解和代码示例 PHP 外观模式讲解和代码示例 Python 外观模式讲解和代码示例 Ruby 外观模式讲解和代码示例 Rust 外观模式讲解和代码示例 Swift 外观模式讲解和代码示例 TypeScript 外观模式讲解和代码示例