c++ qt 聊天系统

以下是一个使用C++和QT开发的简单聊天系统的示例：

#include <QtWidgets/QApplication>
#include <QtWidgets/QTextEdit>
#include <QtWidgets/QLineEdit>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QVBoxLayout>
#include <QtNetwork/QTcpSocket>
#include <QtNetwork/QTcpServer>
#include <QtNetwork/QHostAddress>
#include <QtNetwork/QNetworkInterface>
#include <QtCore/QList>

class ChatServer : public QTcpServer {
    Q_OBJECT
public:
    ChatServer(QObject *parent = 0) : QTcpServer(parent) {}

protected:
    void incomingConnection(qintptr socketDescriptor) {
        ChatSocket *socket = new ChatSocket(this);
        socket->setSocketDescriptor(socketDescriptor);
        emit newConnection(socket);
    }

signals:
    void newConnection(ChatSocket *socket);
};

class ChatSocket : public QTcpSocket {
    Q_OBJECT
public:
    ChatSocket(QObject *parent = 0) : QTcpSocket(parent) {
        connect(this, SIGNAL(readyRead()), this, SLOT(readData()));
        connect(this, SIGNAL(disconnected()), this, SLOT(deleteLater()));
    }

public slots:
    void readData() {
        while (canReadLine()) {
            QByteArray line = readLine();
            emit messageReceived(line);
        }
    }

    void sendMessage(const QString &message) {
        write(message.toUtf8());
    }

signals:
    void messageReceived(const QString &message);
};

class ChatWindow : public QWidget {
    Q_OBJECT
public:
    ChatWindow(QWidget *parent = 0) : QWidget(parent) {
        QVBoxLayout *layout = new QVBoxLayout(this);
        messages = new QTextEdit(this);        messages->setReadOnly(true);
        layout->addWidget(messages);
        QHBoxLayout *inputLayout = new QHBoxLayout();
        input = new QLineEdit(this);
        inputLayout->addWidget(input);
        QPushButton *sendButton = new QPushButton(tr("Send"), this);
        inputLayout->addWidget(sendButton);
        layout->addLayout(inputLayout);
        connect(sendButton, SIGNAL(clicked()), this, SLOT(sendMessage()));
    }

    void setSocket(ChatSocket *socket) {
        connect(socket, SIGNAL(messageReceived(QString)), this, SLOT(receiveMessage(QString)));
        connect(this, SIGNAL(sendMessage(QString)), socket, SLOT(sendMessage(QString)));
    }

public slots:
    void receiveMessage(const QString &message) {
        messages->append(message);
    }

    void sendMessage() {
        QString message = input->text();
        emit sendMessage(message);
        input->clear();
    }

private:
    QTextEdit *messages;
    QLineEdit *input;
};

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    ChatServer server;
    QList<QHostAddress> addresses = QNetworkInterface::allAddresses();
    for (int i = 0; i < addresses.size(); i++) {
        if (addresses[i].protocol() == QAbstractSocket::IPv4Protocol && !addresses[i].isLoopback()) {
            server.listen(addresses[i], 1234);
            break;
        }
    }
    ChatWindow window;
    QObject::connect(&server, SIGNAL(newConnection(ChatSocket*)), &window, SLOT(setSocket(ChatSocket*)));
    window.show();
    return app.exec();
}

这个聊天系统使用QTcpServer和QTcpSocket类来处理客户端连接和消息传递。服务器监听来自局域网下的客户端连接，并将消息转发给所有连接的客户端。客户端可以发送消息并接收其他客户端发送的消息。