Qt 5.13 | Qt WebSockets | QWebSocket client example

Qt 5.13.2 Reference Documentation

# QWebSocket client example

## Description

The EchoClient example implements a WebSocket client that sends a message to a WebSocket server and dumps the answer that it gets back. This example should ideally be used with the EchoServer example.

## Code

We start by connecting to the `connected()` signal.

      EchoClient::EchoClient(const QUrl &url, bool debug, QObject *parent) :
          QObject(parent),
          m_url(url),
          m_debug(debug)
      {
          if (m_debug)
              qDebug() << "WebSocket server:" << url;
          connect(&m_webSocket, &QWebSocket::connected, this, &EchoClient::onConnected);
          connect(&m_webSocket, &QWebSocket::disconnected, this, &EchoClient::closed);
          m_webSocket.open(QUrl(url));
      }

After the connection, we open the socket to the given url.

      void EchoClient::onConnected()
      {
          if (m_debug)
              qDebug() << "WebSocket connected";
          connect(&m_webSocket, &QWebSocket::textMessageReceived,
                  this, &EchoClient::onTextMessageReceived);
          m_webSocket.sendTextMessage(QStringLiteral("Hello, world!"));
      }

When the client is connected successfully, we connect to the `onTextMessageReceived()` signal, and send out "Hello, world!". If connected with the EchoServer, we will receive the same message back.

      void EchoClient::onTextMessageReceived(QString message)
      {
          if (m_debug)
              qDebug() << "Message received:" << message;
          m_webSocket.close();
      }

Whenever a message is received, we write it out.