Qt举一个socket的编程例子

下面是一个简单的Qt socket编程的例子，它创建一个客户端和一个服务器端，通过socket进行通信。

服务器端代码：

#include <QtNetwork>
#include <QObject>

class Server : public QObject
{
    Q_OBJECT

public:
    Server(QObject *parent = nullptr)
        : QObject(parent)
    {
        server = new QTcpServer(this);
        connect(server, &QTcpServer::newConnection, this, &Server::newConnection);

        if (!server->listen(QHostAddress::Any, 1234)) {
            qDebug() << "Server could not start!";
        } else {
            qDebug() << "Server started!";
        }
    }

public slots:
    void newConnection()
    {
        QTcpSocket *socket = server->nextPendingConnection();
        connect(socket, &QTcpSocket::readyRead, this, &Server::readyRead);
        connect(socket, &QTcpSocket::disconnected, socket, &QTcpSocket::deleteLater);

        socket->write("Hello client!");
        socket->flush();
        socket->waitForBytesWritten(3000);
    }

    void readyRead()
    {
        QTcpSocket *socket = qobject_cast<QTcpSocket *>(sender());
        if (socket) {
            qDebug() << "Message from client: " << socket->readAll();
        }
    }

private:
    QTcpServer *server;
};

客户端代码：

#include <QtNetwork>
#include <QObject>

class Client : public QObject
{
    Q_OBJECT

public:
    Client(QObject *parent = nullptr)
        : QObject(parent)
    {
        socket = new QTcpSocket(this);
        connect(socket, &QTcpSocket::connected, this, &Client::connected);
        connect(socket, &QTcpSocket::disconnected, this, &Client::disconnected);
        connect(socket, &QTcpSocket::readyRead, this, &Client::readyRead);

        socket->connectToHost("127.0.0.1", 1234);
    }

public slots:
    void connected()
    {
        qDebug() << "Connected to server!";
    }

    void disconnected()
    {
        qDebug() << "Disconnected from server!";
    }

    void readyRead()
    {
        qDebug() << "Message from server: " << socket->readAll();
    }

private:
    QTcpSocket *socket;
};

在主函数中创建一个服务器和一个客户端实例：

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

    Server server;
    Client client;

    return a.exec();
}

运行程序后，服务器会监听1234端口，并等待客户端连接。客户端会尝试连接到服务器，并接收来自服务器的消息