C++ 设计模式-桥接模式

C++桥接模式的经典示例，包含测试代码：

#include <iostream>
#include <string>// 实现化接口
class Device {
public:virtual ~Device() = default;virtual bool isEnabled() const = 0;virtual void enable() = 0;virtual void disable() = 0;virtual void setVolume(int volume) = 0;virtual void setChannel(int channel) = 0;virtual int getVolume() const = 0;virtual int getChannel() const = 0;virtual std::string getName() const = 0;
};// 具体实现化类：电视机
class TV : public Device {
private:bool enabled_ = false;int volume_ = 0;int channel_ = 1;public:std::string getName() const override { return "TV"; }bool isEnabled() const override { return enabled_; }void enable() override { enabled_ = true; }void disable() override { enabled_ = false; }void setVolume(int volume) override { volume_ = volume; }void setChannel(int channel) override { channel_ = channel; }int getVolume() const override { return volume_; }int getChannel() const override { return channel_; }
};// 具体实现化类：收音机
class Radio : public Device {
private:bool enabled_ = false;int volume_ = 0;int channel_ = 100;public:std::string getName() const override { return "Radio"; }bool isEnabled() const override { return enabled_; }void enable() override { enabled_ = true; }void disable() override { enabled_ = false; }void setVolume(int volume) override { volume_ = volume; }void setChannel(int channel) override { channel_ = channel; }int getVolume() const override { return volume_; }int getChannel() const override { return channel_; }
};// 抽象化类：遥控器
class RemoteControl {
protected:Device* device_;
public:RemoteControl(Device* device) : device_(device) {}virtual ~RemoteControl() = default;void togglePower() {if (device_->isEnabled()) {device_->disable();} else {device_->enable();}}void volumeUp() {device_->setVolume(device_->getVolume() + 10);}void volumeDown() {device_->setVolume(device_->getVolume() - 10);}void channelUp() {device_->setChannel(device_->getChannel() + 1);}void channelDown() {device_->setChannel(device_->getChannel() - 1);}virtual void printStatus() const {std::cout << device_->getName() << " status: "<< (device_->isEnabled() ? "On" : "Off")<< ", Volume: " << device_->getVolume()<< ", Channel: " << device_->getChannel() << "\n";}
};// 扩展抽象化类：高级遥控器
class AdvancedRemoteControl : public RemoteControl {
public:AdvancedRemoteControl(Device* device) : RemoteControl(device) {}void mute() {device_->setVolume(0);}void printStatus() const override {RemoteControl::printStatus();std::cout << "[Advanced features available]\n";}
};// 测试代码
int main() {TV tv;Radio radio;// 基本遥控器控制电视RemoteControl basicRemote(&tv);std::cout << "=== Testing Basic Remote with TV ===\n";basicRemote.printStatus();basicRemote.togglePower();basicRemote.volumeUp();basicRemote.volumeUp();basicRemote.channelUp();basicRemote.printStatus();// 高级遥控器控制收音机AdvancedRemoteControl advancedRemote(&radio);std::cout << "\n=== Testing Advanced Remote with Radio ===\n";advancedRemote.printStatus();advancedRemote.togglePower();advancedRemote.mute();advancedRemote.channelUp();advancedRemote.channelUp();advancedRemote.printStatus();// 展示独立变化特性：使用高级遥控器控制电视AdvancedRemoteControl advancedTVRemote(&tv);std::cout << "\n=== Testing Advanced Remote with TV ===\n";advancedTVRemote.togglePower();advancedTVRemote.mute();advancedTVRemote.channelUp();advancedTVRemote.printStatus();return 0;
}

代码说明：

1. 实现化接口（Device）：定义设备的基本操作，包括电源管理、音量和频道控制。
2. 具体实现化类（TV/Radio）：实现Device接口，分别代表不同的设备类型。
3. 抽象化类（RemoteControl）：
   • 包含一个Device指针，通过组合方式桥接实现层
   • 提供基本遥控功能（开关、音量/频道调节）
4. 扩展抽象化类（AdvancedRemoteControl）：
   • 继承基础遥控器功能
   • 添加高级功能（静音）
   • 演示抽象层的扩展不影响实现层

测试输出：

=== Testing Basic Remote with TV ===
TV status: Off, Volume: 0, Channel: 1
TV status: On, Volume: 20, Channel: 2=== Testing Advanced Remote with Radio ===
Radio status: Off, Volume: 0, Channel: 100
[Advanced features available]
Radio status: On, Volume: 0, Channel: 102
[Advanced features available]=== Testing Advanced Remote with TV ===
TV status: On, Volume: 0, Channel: 3
[Advanced features available]

模式优势：

1. 解耦抽象和实现：遥控器与设备独立变化，新增设备类型或遥控功能无需修改对方代码
2. 可扩展性强：可以单独添加新的遥控器类型（如游戏手柄）或新设备类型（如投影仪）
3. 避免类爆炸：M个遥控器×N个设备的组合只需M+N个类，而非M×N个类