用qt写一段socket代理层的代码实现两个上位机同时连接两个下位机，两个上位机将向下位机发送命令

以下是一个基本的Qt socket代理层代码示例，实现两个上位机同时连接两个下位机，并向下位机发送命令：

#include <QtNetwork>

class SocketProxy : public QObject
{
    Q_OBJECT
    
public:
    SocketProxy(QObject *parent = nullptr) : QObject(parent) 
    {
        // 创建监听套接字
        server = new QTcpServer(this);
        connect(server, &QTcpServer::newConnection, this, &SocketProxy::acceptConnection);
        if (!server->listen(QHostAddress::Any, 1234)) {
            qDebug() << "Unable to start server:" << server->errorString();
            return;
        }
        
        qDebug() << "Server started, listening on port 1234...";
    }

private slots:
    void acceptConnection()
    {
        // 获取新的传入连接
        QTcpSocket *clientSocket = server->nextPendingConnection();
        qDebug() << "New client connection:" << clientSocket->peerAddress().toString() << clientSocket->peerPort();
        
        // 创建向下位机的连接
        QTcpSocket *downstreamSocket = new QTcpSocket(this);
        downstreamSocket->connectToHost(QHostAddress("192.168.0.1"), 5678);
        qDebug() << "Connecting to downstream server...";
        
        // 将两个套接字连接起来
        connect(clientSocket, &QTcpSocket::readyRead, [=]() {
            QByteArray data = clientSocket->readAll();
            qDebug() << "Received data from client:" << data;
            downstreamSocket->write(data);
        });
        
        connect(downstreamSocket, &QTcpSocket::readyRead, [=]() {
            QByteArray data = downstreamSocket->readAll();
            qDebug() << "Received data from downstream server:" << data;
            clientSocket->write(data);
        });
        
        connect(clientSocket, &QTcpSocket::disconnected, [=]() {
            qDebug() << "Client disconnected:" << clientSocket->peerAddress().toString() << clientSocket->peerPort();
            clientSocket->deleteLater();
            downstreamSocket->deleteLater();
        });
    }

private:
    QTcpServer *server;
};

在上面的示例中，我们首先创建了一个QTcpServer来监听传入的连接。当有新的连接时，我们将客户端套接字和向下位机的套接字连接起来，并建立了数据传输的信号槽连接。当客户端断开连接时，我们将释放与该连接相关的资源。