例1 客户端

#include <QTcpSocket>  
#include <QHostAddress>  int main(int argc, char *argv[])  
{  QApplication app(argc, argv);  QTcpSocket socket;  socket.connectToHost(QHostAddress::LocalHost, 1234);  if (socket.waitForConnected()) {  socket.write("Hello, server!");  if (socket.waitForBytesWritten()) {  if (socket.waitForReadyRead()) {  qDebug() << "Received data:" << socket.readAll();  }  }  }  return app.exec();  
}

例2 服务端

#include <QTcpServer>  
#include <QTcpSocket>  
#include <QMessageBox>  class MyTcpServer : public QTcpServer  
{  Q_OBJECT  public:  explicit MyTcpServer(QObject *parent = 0) : QTcpServer(parent)  {  if (!this->listen(QHostAddress::Any, 1234)) {  QMessageBox::critical(0, "Server Error", "Unable to start the server:" + this->errorString());  exit(EXIT_FAILURE);  }  }  protected:  void incomingConnection(qintptr socketDescriptor) override  {  QTcpSocket* socket = new QTcpSocket(this);  socket->setSocketDescriptor(socketDescriptor);  connect(socket, &QTcpSocket::readyRead, this, [socket]() {  QByteArray data = socket->readAll();  qDebug() << "Received data:" << data;  socket->write("Hello, client!");  });  connect(socket, &QTcpSocket::disconnected, this, [socket]() {  qDebug() << "Client disconnected:" << socket->peerAddress().toString();  socket->deleteLater();  });  }  
};  int main(int argc, char *argv[])  
{  QApplication app(argc, argv);  MyTcpServer server;  return app.exec();  
}

Qt 的 TCP 类（QTcpSocket 和 QTcpServer）创建简单的 TCP 客户端和服务器。在示例 1 中，我们创建了一个 TCP 客户端，连接到本地主机上的端口 1234，并发送一条消息给服务器。在示例 2 中，我们创建了一个 TCP 服务器，监听本地主机上的端口 1234，并在接收到客户端连接时发送一条消息给客户端。这些示例可以作为你开始使用 Qt TCP 通信的基础。