qt使用tcp互发信息

在Qt中，使用TCP进行双向通信需要两个部分：服务器和客户端。这里是一个简单的例子展示如何让它们互相发送信息。

**服务器（Server.cpp）:**

#include <QTcpServer>
#include <QDataStream>
#include <QObject>

class Server : public QObject {
    Q_OBJECT
public slots:
    void processClientMessage(const QByteArray &message) {
        // 对接收到的消息进行处理
        emit messageReceived(message);
    }

signals:
    void messageReceived(const QByteArray &message);

private:
    QTcpServer *server;
    QQueue<QByteArray> messages; // 存储来自客户端的消息队列
};

**服务器端主程序:**

void Server::handleNewConnection() {
    QTcpSocket *clientSocket = server->nextPendingConnection();
    connect(clientSocket, &QTcpSocket::readyRead, this, [this](QTcpSocket *socket) {
        QByteArray buffer = socket->readAll();
        processClientMessage(buffer);
    });
    connect(clientSocket, &QTcpSocket::disconnected, this, &Server::closeConnection);
}

// 接收并广播接收到的消息
void Server::messageReceived(const QByteArray &message) {
    emit broadcastMessage(message);
}

void Server::broadcastMessage(const QByteArray &message) {
    for (auto client : clients) {
        client->write(message);
    }
}

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Server server;
    return app.exec();
}

**客户端（Client.cpp）:**

#include <QTcpSocket>
#include <QDataStream>
#include <QObject>

class Client : public QObject {
    Q_OBJECT

public slots:
    void sendMessage(const QByteArray &message) {
        connectedSocket.write(message);
    }

private:
    QTcpSocket *connectedSocket;
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Client client;
    client.connectedSocket = new QTcpSocket(&client);
    connect(client.connectedSocket, &QTcpSocket::connected, &client, []{
        client.sendMessage("Client is ready to send");
    });
    connect(client.connectedSocket, &QTcpSocket::disconnected, &app, &QApplication::quit);

    // 连接到服务器
    if (!client.connectedSocket->connectToHost("localhost", 12345)) {
        qDebug() << "Failed to connect to the server.";
        return -1;
    }

    return app.exec();
}

在这个例子中，服务器接收客户端发送的信息，将其存储然后通过`messageReceived`信号广播给其他已连接的客户端。客户端则在连接上建立后发送一条消息。