用qt写一段代码实现两个电脑上的上位机通过代理连接两个下位机，两个下位机收到命令后会发送的数据，发送的数据会在两台上位机上同时显示出来

以下是一个简单的使用Qt实现的示例代码，实现了两个上位机通过代理连接两个下位机，并实时交换收到的数据：

#include <QtNetwork>

class Proxy : public QObject
{
    Q_OBJECT
public:
    Proxy(QObject *parent = nullptr) : QObject(parent)
    {
        // 创建代理服务器
        m_proxyServer = new QTcpServer(this);
        connect(m_proxyServer, &QTcpServer::newConnection, this, &Proxy::onNewConnection);
        if (!m_proxyServer->listen(QHostAddress::Any, 1234)) {
            qWarning() << "Error: " << m_proxyServer->errorString();
            return;
        }
        qDebug() << "Proxy server started on port 1234";
    }

private slots:
    void onNewConnection()
    {
        // 接收到新的客户端连接
        QTcpSocket *clientSocket = m_proxyServer->nextPendingConnection();
        qDebug() << "Client connected from" << clientSocket->peerAddress() << clientSocket->peerPort();

        // 建立到目标服务器的连接
        QTcpSocket *targetSocket = new QTcpSocket(this);
        connect(targetSocket, &QTcpSocket::connected, this, &Proxy::onTargetConnected);
        connect(targetSocket, &QTcpSocket::disconnected, this, &Proxy::onTargetDisconnected);
        connect(targetSocket, &QTcpSocket::readyRead, this, &Proxy::onTargetDataReady);
        m_targetSockets.insert(clientSocket, targetSocket);
        targetSocket->connectToHost(QHostAddress("192.168.1.2"), 5678);
    }

    void onTargetConnected()
    {
        // 目标服务器连接成功
        QTcpSocket *targetSocket = qobject_cast<QTcpSocket*>(sender());
        QTcpSocket *clientSocket = m_targetSockets.key(targetSocket);
        qDebug() << "Connected to target server from" << clientSocket->peerAddress() << clientSocket->peerPort();
    }

    void onTargetDisconnected()
    {
        // 目标服务器连接断开
        QTcpSocket *targetSocket = qobject_cast<QTcpSocket*>(sender());
        QTcpSocket *clientSocket = m_targetSockets.key(targetSocket);
        qDebug() << "Disconnected from target server from" << clientSocket->peerAddress() << clientSocket->peerPort();
        m_targetSockets.remove(clientSocket);
        targetSocket->deleteLater();
    }

    void onTargetDataReady()
    {
        // 接收到目标服务器发送的数据，转发到客户端
        QTcpSocket *targetSocket = qobject_cast<QTcpSocket*>(sender());
        QTcpSocket *clientSocket = m_targetSockets.key(targetSocket);
        QByteArray data = targetSocket->readAll();
        clientSocket->write(data);
        qDebug() << "Received data from target server:" << data;
    }

private:
    QTcpServer *m_proxyServer;
    QMap<QTcpSocket*, QTcpSocket*> m_targetSockets;
};

class Client : public QObject
{
    Q_OBJECT
public:
    Client(const QString &address, quint16 port, QObject *parent = nullptr) : QObject(parent)
    {
        // 创建客户端连接到代理服务器
        m_clientSocket = new QTcpSocket(this);
        connect(m_clientSocket, &QTcpSocket::connected, this, &Client::onConnected);
        connect(m_clientSocket, &QTcpSocket::disconnected, this, &Client::onDisconnected);
        connect(m_clientSocket, &QTcpSocket::readyRead, this, &Client::onDataReady);
        m_clientSocket->connectToHost(address, port);
    }

private slots:
    void onConnected()
    {
        // 客户端连接成功
        qDebug() << "Connected to proxy server";
    }

    void onDisconnected()
    {
        // 客户端连接断开
        qDebug() << "Disconnected from proxy server";
    }

    void onDataReady()
    {
        // 接收到代理服务器发送的数据，显示在界面上并转发到目标服务器
        QByteArray data = m_clientSocket->readAll();
        qDebug() << "Received data from proxy server:" << data;
        m_targetSocket->write(data);
    }

private:
    QTcpSocket *m_clientSocket;
    QTcpSocket *m_targetSocket;
};

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

    // 创建代理服务器
    Proxy proxy;

    // 创建两个上位机连接到代理服务器
    Client client1("127.0.0.1", 1234);
    Client client2("127.0.0.1", 1234);

    // 创建两个下位机等待连接
    QTcpServer targetServer;
    targetServer.listen(QHostAddress::Any, 5678);
    QObject::connect(&targetServer, &QTcpServer::newConnection, [&](){
        QTcpSocket *targetSocket = targetServer.nextPendingConnection();
        qDebug() << "Target connected from" << targetSocket->peerAddress() << targetSocket->peerPort();
        QObject::connect(targetSocket, &QTcpSocket::disconnected, [=](){
            qDebug() << "Target disconnected from" << targetSocket->peerAddress() << targetSocket->peerPort();
            targetSocket->deleteLater();
        });
        QObject::connect(targetSocket, &QTcpSocket::readyRead, [=](){
            QByteArray data = targetSocket->readAll();
            qDebug() << "Received data from target:" << data;
            client1.write(data);
            client2.write(data);
        });
    });

    return app.exec();
}

注意：该示例代码仅供参考，需要根据实际情况进行修改和完善。