在QT环境下，封装一个TCP服务端监听端口，收发消息的工具类

以下是一个基本的TCP服务端监听端口，收发消息的工具类的封装示例，使用QT的QTcpServer和QTcpSocket实现：

#include <QObject>
#include <QTcpServer>
#include <QTcpSocket>
#include <QDebug>

class TcpServer : public QObject
{
    Q_OBJECT

public:
    explicit TcpServer(QObject *parent = nullptr) : QObject(parent)
    {
        server = new QTcpServer(this);

        connect(server, &QTcpServer::newConnection, this, &TcpServer::newConnection);
    }

    ~TcpServer()
    {
        server->close();
        delete server;
    }

    bool listen(int port)
    {
        return server->listen(QHostAddress::Any, port);
    }

signals:
    void clientConnected(QTcpSocket *socket);
    void clientDisconnected(QTcpSocket *socket);
    void messageReceived(QTcpSocket *socket, const QByteArray &message);

private slots:
    void newConnection()
    {
        QTcpSocket *socket = server->nextPendingConnection();

        connect(socket, &QTcpSocket::disconnected, this, &TcpServer::clientDisconnected);
        connect(socket, &QTcpSocket::readyRead, this, &TcpServer::readyRead);

        emit clientConnected(socket);
    }

    void readyRead()
    {
        QTcpSocket *socket = static_cast<QTcpSocket *>(sender());

        while (socket->bytesAvailable() > 0)
        {
            QByteArray data = socket->readAll();

            emit messageReceived(socket, data);
        }
    }

private:
    QTcpServer *server;
};

使用示例：

TcpServer tcpServer;

connect(&tcpServer, &TcpServer::clientConnected, this, &MyClass::onClientConnected);
connect(&tcpServer, &TcpServer::clientDisconnected, this, &MyClass::onClientDisconnected);
connect(&tcpServer, &TcpServer::messageReceived, this, &MyClass::onMessageReceived);

if (!tcpServer.listen(1234))
{
    qWarning() << "Failed to listen on port 1234";
}

void MyClass::onClientConnected(QTcpSocket *socket)
{
    qDebug() << "Client connected:" << socket->peerAddress().toString() << ":" << socket->peerPort();
}

void MyClass::onClientDisconnected(QTcpSocket *socket)
{
    qDebug() << "Client disconnected:" << socket->peerAddress().toString() << ":" << socket->peerPort();
}

void MyClass::onMessageReceived(QTcpSocket *socket, const QByteArray &message)
{
    qDebug() << "Message received from" << socket->peerAddress().toString() << ":" << socket->peerPort() << ":" << message;
}

这个工具类会监听指定的端口，并在有新的客户端连接时发出信号，同时也会在客户端断开连接时发出信号。当收到客户端的消息时，会发出信号，同时将消息的内容和发送消息的客户端对应的QTcpSocket对象一起传递给槽函数。可以在槽函数中处理收到的消息，回复客户端，或者进行其他操作。