qt嵌入式html和本地c++通信方式

前沿：我们在做qt项目的时候，通常会把某个html网页直接显示到应用程序中。比如绘图。直接把html形式的图标嵌入到应用程序中

但是我们需要把数据从后台c++端传到html端，实现显示。qt实现了相关的方法

程序运行截图

一。先看客户端js代码

    <script type="text/javascript" src="http://t.zoukankan.com/qwebchannel.js"></script>
    <script type="text/javascript">
        //BEGIN SETUP
        function output(message) {
            var output = document.getElementById("output");
            output.innerHTML = output.innerHTML + message + " ";
        }
        window.onload = function () {
            output("setting up QWebChannel.");
            new QWebChannel(qt.webChannelTransport, function (channel) {
                // make dialog object accessible globally
                var content = channel.objects.content;

                document.getElementById("send").onclick = function () {
                    var input = document.getElementById("input");
                    var text = input.value;
                    if (!text) {
                        return;
                    }
                    output("Sent message: " + text);
                    input.value = "";
                    content.receiveText(text); //该方法实际是调用的后台的slot，后端c++通过slot来接收数据。客户端向后台发数据
                }
                content.sendText.connect(function (message) {  //sendText是后台发送数据的信号signal，该方法实现把后端c++信号signal，与html页面function链接起来，实现后台向前段发送数据。c++端信号与html端的slot链接起来
                    output("Received message: " + message);
                });
                content.receiveText("Client connected, ready to send/receive messages!");
                output("Connected to WebChannel, ready to send/receive messages!");
            });
        }
        //END SETUP
    </script>

二，后台客户端

1.document实现方式

classDocument :publicQObject

{

    Q_OBJECT

    Q_PROPERTY(QString text MEMBER s_text NOTIFY sendText)

public:

    explicit Document(QObject *parent = nullptr) : QObject(parent) {}

    void setSendTextText(const QString &text);

    void setUi(Ui::MainWidget *ui);

public slots:

    void receiveText(const QString &r_text);

signals:

    void sendText(const QString &text); //这两个是重点，一个slot一个signal分别用于接收和发送数据，注意和前端js代码的对应

private:

    void displayMessage(const QString &message);

    QString s_text;

    QString recieve_text;

    Ui::MainWidget *mainUi;

};
document.cpp文件
/****************************************************************************

**

** Copyright (C) 2015 The Qt Company Ltd.

** Contact: http://www.qt.io/licensing/

**

** This file is part of the demonstration applications of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** 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 http://www.qt.io/terms-conditions. For further

** information use the contact form at http://www.qt.io/contact-us.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file. Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** As a special exception, The Qt Company gives you certain additional

** rights. These rights are described in The Qt Company LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** GNU General Public License Usage

** Alternatively, this file may be used under the terms of the GNU

** General Public License version 3.0 as published by the Free Software

** Foundation and appearing in the file LICENSE.GPL included in the

** packaging of this file. Please review the following information to

** ensure the GNU General Public License version 3.0 requirements will be

** met: http://www.gnu.org/copyleft/gpl.html.

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "document.h"

void Document::setSendTextText(const QString &text) //向html页面发送数据

{

    s_text = text;

    emit sendText(s_text);

}

void Document::displayMessage(const QString &message)//接收来自html页面的数据

{

      mainUi->editor->appendPlainText(message);

}

/*!

    This slot is invoked from the HTML client side and the text displayed on the server side.

*/

void Document::receiveText(const QString &r_text)

{

    displayMessage(QObject::tr("Received message: %1").arg(r_text));

}

void Document::setUi(Ui::MainWidget *ui)

{

    mainUi = ui;

}

二，使用document文件并创建webchannel
MainWidget::MainWidget(QWidget *parent) :

    QWidget(parent),

    ui(new Ui::MainWidget)

{

    ui->setupUi(this);

//    PreviewPage *page = new PreviewPage(this);

//    ui->preview->setPage(page);

    m_content.setUi(ui);

    QWebChannel *channel = new QWebChannel(this);

    channel->registerObject(QStringLiteral("content"), &m_content);

    //page->setWebChannel(channel);

    ui->preview->page()->setWebChannel(channel);

    ui->preview->setUrl(QUrl("qrc:/HelloWorld2.html"));

    //ui->preview->setUrl(QUrl("qrc:/index.html"));

    ui->editor->setPlainText("hello...
");

}
这边是后端界面的ui文件，通过上述代码就是实现了c++端document类与客户端html通信。
详细的实例代码大家可以到一下链接下载：http://download.csdn.net/download/soft_123456/10115764
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