qt websocket 通讯实现消息发送接收

websocket 是基于 TCP socket 之上的应用层，解决 HTML 轮询连接的问题，实现客户端与服务端长连接，实现消息互相发送，全双工。

服务端，使用 QT 教程demo
chatserver.h


#ifndef CHATSERVER_H
#define CHATSERVER_H#include <QtCore/QObject>
#include <QtCore/QList>QT_FORWARD_DECLARE_CLASS(QWebSocketServer)
QT_FORWARD_DECLARE_CLASS(QWebSocket)
QT_FORWARD_DECLARE_CLASS(QString)class ChatServer : public QObject
{Q_OBJECT
public:explicit ChatServer(quint16 port, QObject *parent = nullptr);~ChatServer() override;private slots:void onNewConnection();void processMessage(const QString &message);void socketDisconnected();private:QWebSocketServer *m_pWebSocketServer;QList<QWebSocket *> m_clients;
};#endif //CHATSERVER_H

chatserver.cpp

/****************************************************************************
**
** Copyright (C) 2016 Kurt Pattyn <pattyn.kurt@gmail.com>.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtWebSockets module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "chatserver.h"#include <QtWebSockets>
#include <QtCore>#include <cstdio>
using namespace std;QT_USE_NAMESPACEstatic QString getIdentifier(QWebSocket *peer)
{return QStringLiteral("%1:%2").arg(peer->peerAddress().toString(),QString::number(peer->peerPort()));
}//! [constructor]
ChatServer::ChatServer(quint16 port, QObject *parent) :QObject(parent),m_pWebSocketServer(new QWebSocketServer(QStringLiteral("Chat Server"),QWebSocketServer::NonSecureMode,this))
{if (m_pWebSocketServer->listen(QHostAddress::Any, port)){QTextStream(stdout) << "Chat Server listening on port " << port << '\n';connect(m_pWebSocketServer, &QWebSocketServer::newConnection,this, &ChatServer::onNewConnection);}
}ChatServer::~ChatServer()
{m_pWebSocketServer->close();
}
//! [constructor]//! [onNewConnection]
void ChatServer::onNewConnection()
{auto pSocket = m_pWebSocketServer->nextPendingConnection();QTextStream(stdout) << getIdentifier(pSocket) << " connected!\n";pSocket->setParent(this);// 对连接进来的每一个进行信号槽连接绑定connect(pSocket, &QWebSocket::textMessageReceived,this, &ChatServer::processMessage);connect(pSocket, &QWebSocket::disconnected,this, &ChatServer::socketDisconnected);// 使用 list 进行管理，方便断开m_clients << pSocket;
}
//! [onNewConnection]//! [processMessage]
void ChatServer::processMessage(const QString &message)
{QWebSocket *pSender = qobject_cast<QWebSocket *>(sender());for (QWebSocket *pClient : qAsConst(m_clients)) {if (pClient == pSender) //don't echo message back to sender{pClient->sendTextMessage(message + " @ host echo ");qDebug() << "peer address = " << pClient->peerAddress();}}QTextStream(stdout) << "received msg: " << message << std::endl;
}
//! [processMessage]//! [socketDisconnected]
void ChatServer::socketDisconnected()
{QWebSocket *pClient = qobject_cast<QWebSocket *>(sender());QTextStream(stdout) << getIdentifier(pClient) << " disconnected!\n";if (pClient){m_clients.removeAll(pClient);pClient->deleteLater();}
}
//! [socketDisconnected]

main.cpp

#include <QtCore/QCoreApplication>#include "chatserver.h"int main(int argc, char *argv[])
{QCoreApplication a(argc, argv);ChatServer server(1234);return a.exec();
}

客户端
clientwidget.h

#ifndef CLIENTWIDGET_H
#define CLIENTWIDGET_H#include <QWidget>
#include "WebsocketClient.h"QT_FORWARD_DECLARE_CLASS(QWebSocketClient)
QT_FORWARD_DECLARE_CLASS(QWebSocket)namespace Ui {
class ClientWidget;
}class ClientWidget : public QWidget
{Q_OBJECTpublic:explicit ClientWidget(QWidget *parent = 0);~ClientWidget();private slots:void on_pushButton_clicked();void on_pushButton_2_clicked();void slot_recvMsg(QString msg);private:Ui::ClientWidget *ui;WebsocketClient m_client;
};#endif // CLIENTWIDGET_H

clientwidget.cpp

#include "ClientWidget.h"
#include "ui_ClientWidgetwidget.h"ClientWidget::ClientWidget(QWidget *parent) :QWidget(parent),ui(new Ui::ClientWidget)
{ui->setupUi(this);}ClientWidget::~ClientWidget()
{delete ui;
}void ClientWidget::on_pushButton_clicked()
{m_client.connectToServer();connect(&m_client, &WebsocketClient::sig_newMsg, this, &ClientWidget::slot_recvMsg);
}void ClientWidget::on_pushButton_2_clicked()
{m_client.sendMsg(ui->lineEditSendTxt->text());
}void ClientWidget::slot_recvMsg(QString msg)
{ui->textBrowserRecv->append(msg);
}

websocketclient.h

#ifndef WEBSOCKETCLIENT_H
#define WEBSOCKETCLIENT_H#include <QDebug>
#include <QWebSocket>
QT_FORWARD_DECLARE_CLASS(QWebSocketClient)
QT_FORWARD_DECLARE_CLASS(QWebSocket)class WebsocketClient:public QObject
{Q_OBJECT
public:WebsocketClient();//connect to servervoid connectToServer();bool sendMsg(QString msg);void disConnect();public slots:void slot_recvMsg(QString msg);signals:void sig_newMsg(QString msg);private:QWebSocket m_clientSocket;
};#endif // WEBSOCKETCLIENT_H

websocketclient.cpp

#include "WebsocketClient.h"WebsocketClient::WebsocketClient()
{}void WebsocketClient::connectToServer()
{QString urlStr = "ws://127.0.0.1:1234";m_clientSocket.open(QUrl(urlStr));connect(&m_clientSocket, &QWebSocket::textMessageReceived, this, &WebsocketClient::slot_recvMsg);
}bool WebsocketClient::sendMsg(QString msg)
{if (m_clientSocket.sendTextMessage(msg)) {return true;}else {return false;}
}void WebsocketClient::disConnect()
{m_clientSocket.close();
}void WebsocketClient::slot_recvMsg(QString msg)
{qDebug() << "client received from host: " << msg;emit sig_newMsg(msg);
}