qt使用tcp实现客户端与服务器交互数据具体案例

在Qt中，使用TCP套接字（QTcpSocket）可以创建客户端和服务器，用于实现实时的数据交换。下面是一个简单的例子，展示如何在Qt中建立一个TCP客户端和服务器：

**服务器端示例（server.cpp）**:

#include <QTcpServer>
#include <QDebug>

class Server : public QTcpServer
{
public:
    voidincomingConnection(qintptr socketDescriptor)
    {
        QByteArray msg = "Welcome to the server!";
        QDataStream out(&socketDescriptor, QIODevice::WriteOnly);
        out << msg;
        qDebug() << "Connected client with descriptor:" << socketDescriptor;
    }
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Server server;
    if (server.listen(QHostAddress::Any, 8000)) // Listen on any IP and port 8000
    {
        qDebug() << "Server is listening.";
        while (!server.isListening()) {} // Wait for a connection
        return app.exec();
    }
    else
    {
        qWarning() << "Failed to start server.";
        return -1;
    }
}

在这个例子中，服务器监听8000端口，并在连接请求时向新连接的客户端发送欢迎消息。

**客户端示例（client.cpp）**:

#include <QTcpSocket>
#include <QApplication>
#include <QMessageBox>

class Client
{
public:
    voidconnectToServer()
    {
        QTcpSocket* client = new QTcpSocket(this);
        client->connectToHost("localhost", 8000); // Replace with your server's address
        connect(client, &QTcpSocket::connected, this, [client] { client->send("Hello from client!"); });
        connect(client, &QTcpSocket::readyRead, this, [client] {
            QByteArray data;
            client->readAll(data);
            QMessageBox::information(this, "Message", QString::fromStdString(data.toStdString()));
        });
        connect(client, &QTcpSocket::disconnected, this, &Client::onDisconnected);
    }

private:
    void onDisconnected()
    {
        QMessageBox::information(this, "Connection Lost", "The connection was closed.");
    }
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Client client;
    client.connectToServer();
    return app.exec();
}

客户端尝试连接到服务器，一旦连接成功，它会发送一条消息并接收来自服务器的响应。如果连接关闭，会显示相应提示。