使用 Qt5WebSockets 模块来实现 WebSocket 客户端和服务器

WebSocket 服务器

// websocketserver.h
#ifndef WEBSOCKETSERVER_H
#define WEBSOCKETSERVER_H

#include <QObject>
#include <QWebSocketServer>
#include <QWebSocket>

class WebSocketServer : public QObject
{
    Q_OBJECT
public:
    explicit WebSocketServer(quint16 port, QObject *parent = nullptr);
    ~WebSocketServer();

private slots:
    void onNewConnection();
    void processTextMessage(QString message);
    void socketDisconnected();

private:
    QWebSocketServer *m_pWebSocketServer;
    QList<QWebSocket *> m_clients;
};

#endif // WEBSOCKETSERVER_H

// websocketserver.cpp
#include "websocketserver.h"

WebSocketServer::WebSocketServer(quint16 port, QObject *parent) :
    QObject(parent),
    m_pWebSocketServer(new QWebSocketServer(QStringLiteral("Echo Server"),
                                            QWebSocketServer::NonSecureMode,
                                            this))
{
    if (m_pWebSocketServer->listen(QHostAddress::Any, port)) {
        connect(m_pWebSocketServer, &QWebSocketServer::newConnection,
                this, &WebSocketServer::onNewConnection);
        qDebug() << "WebSocket server listening on port" << port;
    }
}

WebSocketServer::~WebSocketServer()
{
    m_pWebSocketServer->close();
    qDeleteAll(m_clients.begin(), m_clients.end());
}

void WebSocketServer::onNewConnection()
{
    QWebSocket *pSocket = m_pWebSocketServer->nextPendingConnection();

    connect(pSocket, &QWebSocket::textMessageReceived,
            this, &WebSocketServer::processTextMessage);
    connect(pSocket, &QWebSocket::disconnected,
            this, &WebSocketServer::socketDisconnected);

    m_clients << pSocket;
}

void WebSocketServer::processTextMessage(QString message)
{
    QWebSocket *pSender = qobject_cast<QWebSocket *>(sender());
    if (pSender) {
        pSender->sendTextMessage(message); // Echo message back to sender
    }
}

void WebSocketServer::socketDisconnected()
{
    QWebSocket *pClient = qobject_cast<QWebSocket *>(sender());
    if (pClient) {
        m_clients.removeAll(pClient);
        pClient->deleteLater();
    }
}

WebSocket 客户端

// websocketclient.h
#ifndef WEBSOCKETCLIENT_H
#define WEBSOCKETCLIENT_H

#include <QObject>
#include <QWebSocket>

class WebSocketClient : public QObject
{
    Q_OBJECT
public:
    explicit WebSocketClient(const QUrl &url, QObject *parent = nullptr);

private slots:
    void onConnected();
    void onTextMessageReceived(QString message);

private:
    QWebSocket m_webSocket;
    QUrl m_url;
};

#endif // WEBSOCKETCLIENT_H

// websocketclient.cpp
#include "websocketclient.h"
#include <QDebug>

WebSocketClient::WebSocketClient(const QUrl &url, QObject *parent) :
    QObject(parent),
    m_url(url)
{
    connect(&m_webSocket, &QWebSocket::connected,
            this, &WebSocketClient::onConnected);
    connect(&m_webSocket, &QWebSocket::disconnected,
            this, [](){ qDebug() << "WebSocket disconnected"; });

    m_webSocket.open(QUrl(url));
}

void WebSocketClient::onConnected()
{
    qDebug() << "WebSocket connected";
    connect(&m_webSocket, &QWebSocket::textMessageReceived,
            this, &WebSocketClient::onTextMessageReceived);

    m_webSocket.sendTextMessage(QStringLiteral("Hello, world!"));
}

void WebSocketClient::onTextMessageReceived(QString message)
{
    qDebug() << "Message received:" << message;
}

main.cpp

#include <QCoreApplication>
#include "websocketserver.h"
#include "websocketclient.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    WebSocketServer server(1234); // 创建服务器，监听端口 1234
    WebSocketClient client(QUrl(QStringLiteral("ws://localhost:1234"))); // 创建客户端，连接到服务器

    return a.exec();
}

代码说明

1. WebSocketServer 类：实现了一个简单的 WebSocket 服务器。服务器监听新连接，并回显收到的消息。
2. WebSocketClient 类：实现了一个简单的 WebSocket 客户端。客户端连接到服务器，发送一条消息，并输出接收到的消息。
3. main.cpp：启动 WebSocket 服务器和客户端。