QWebEngine_C++_交互

参考网址：http://blog.csdn.net/liuyez123/article/details/50509788
　　ZC: 该文章里面的：
　　“
　　　　<ahref="javascript:document.getElementByIdx_x("myLabel").setText("通过JavaScript访问Qt对象");"mce_href="javascript:document.getElementByIdx_x("myLabel").setText("通过JavaScript访问Qt对象");">点击访问Qt对象</a>
　　”
　　　　貌似使用的机制是 "WebKik & QWebPluginFactory"，貌似在WebEngine中暂时(至20160926为止)还没有...
https://www.google.com.hk 搜索 “getElementByIdx_x("myLabel").setText QT”得到 仅有的4个结果：
　　http://www.programgo.com/article/54841979099/
　　http://blog.hehehehehe.cn/a/10652.htm
　　http://www.360doc.com/content/16/0405/18/13792507_548095953.shtml
　　http://blog.inet198.cn/?liuyez123/article/details/50509788

1、我的代码：

　　1.1、pro

QT       += core gui    \
webenginewidgets webchannel
CONFIG += c++11

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = QWebEngine_JiaoHu
TEMPLATE = app

SOURCES += main.cpp\
mainwindow.cpp \
document.cpp \
previewpage.cpp

HEADERS  += mainwindow.h \
document.h \
previewpage.h

FORMS    += mainwindow.ui

　　1.2、main.cpp ==> 默认

　　1.3、mainwindow.h 和 mainwindow.cpp

　　　　1.3.1、mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "document.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private slots:
void on_pushButton_clicked();

private:
Ui::MainWindow *ui;

private:
bool isModified() const;
Document m_content;
};

#endif // MAINWINDOW_H

　　　　1.3.2、mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include "previewpage.h"
#include <QWebChannel>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
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->setUrl(QUrl("qrc:/index.html"));
ui->preview->setUrl(QUrl::fromUserInput("F:/ZZ_Qt5/QWebEngine_JiaoHu/html/index.html"));

ui->editor->setPlainText("hello...\n");
}

MainWindow::~MainWindow()
{
delete ui;
}

bool MainWindow::isModified() const
{
return ui->editor->document()->isModified();
}

void MainWindow::on_pushButton_clicked()
{
m_content.setSendTextText(ui->lineEdit->text());
}

　　1.4、previewpage.h 和 previewpage.cpp ==> 用于在 打开网页的时候，做一下处理(相当于过滤层) ：如果网址 如何要求就通过(打开网页)，如果 网址不符合要求 就拒绝(不打开网页)

　　　　1.4.1、previewpage.h

#ifndef PREVIEWPAGE_H
#define PREVIEWPAGE_H

#include <QWebEnginePage>

class PreviewPage : public QWebEnginePage
{
Q_OBJECT
public:
explicit PreviewPage(QObject *parent = nullptr) : QWebEnginePage(parent) {}

protected:
bool acceptNavigationRequest(const QUrl &url, NavigationType type, bool isMainFrame);
};

#endif // PREVIEWPAGE_H

　　　　1.4.2、previewpage.cpp

#include "previewpage.h"

#include <QDesktopServices>

bool PreviewPage::acceptNavigationRequest(const QUrl &url,
QWebEnginePage::NavigationType /*type*/,
bool /*isMainFrame*/)
{
// Only allow qrc:/index.html.
if (url.scheme() == QString("qrc"))
return true;
//QDesktopServices::openUrl(url); // ZC: 这一句代码，会打开 本地的默认浏览器，显示相关的网页
//return false; // ZC: 返回 false的话，就不打开 相应的网页
return true;    // ZC: 返回 false的话，就打开 相应的网页
}

　　1.5、document.h 和 document.cpp ==> 这个是 JS和C++交互的类

　　　　1.5.1、document.h

#ifndef DOCUMENT_H
#define DOCUMENT_H

#include <QObject>
#include <QString>
#include "ui_mainwindow.h"

namespace Ui {
class MainWidget;
}

class Document : public QObject
{
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::MainWindow *ui);

public slots:
void receiveText(const QString &r_text);

signals:
void sendText(const QString &text);

private:
void displayMessage(const QString &message);
QString s_text;
QString recieve_text;
Ui::MainWindow *mainUi;
};

#endif // DOCUMENT_H

　　　　1.5.2、document.cpp

#include "document.h"
#include <QDebug>

void Document::setSendTextText(const QString &text)
{
s_text = text;
qDebug() << "Document::setSendTextText" << s_text;
emit sendText(s_text);
}

void Document::displayMessage(const QString &message)
{
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::MainWindow *ui)
{
mainUi = ui;
}

　　1.6、网页 源码

　　　　1.6.1、index.html

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript" src="./qwebchannel.js"></script>
<script type="text/javascript">
//BEGIN SETUP
function output(message)
{
var output = document.getElementById("output");
output.innerHTML = output.innerHTML + message + "\n";
}
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);
}

content.sendText.connect(function(message) {
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>
<style type="text/css">
html {
height: 100%;
width: 100%;
}
#input {
width: 400px;
margin: 0 10px 0 0;
}
#send {
width: 90px;
margin: 0;
}
#output {
width: 500px;
height: 300px;
}
</style>
</head>
<body>
<textarea id="output"></textarea><br />
<input id="input" /><input type="submit" id="send" value="Send" onclick="javascript:click();" />
</body>
</html>

　　　　1.6.2、qwebchannel.js

/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Copyright (C) 2014 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com>
** Contact: http://www.qt.io/licensing/ **
** This file is part of the QtWebChannel module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** 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 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** 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.
**
** $QT_END_LICENSE$
**
****************************************************************************/

"use strict";

var QWebChannelMessageTypes = {
signal: 1,
propertyUpdate: 2,
init: 3,
idle: 4,
debug: 5,
invokeMethod: 6,
connectToSignal: 7,
disconnectFromSignal: 8,
setProperty: 9,
response: 10,
};

var QWebChannel = function(transport, initCallback)
{
if (typeof transport !== "object" || typeof transport.send !== "function") {
console.error("The QWebChannel expects a transport object with a send function and onmessage callback property." +
" Given is: transport: " + typeof(transport) + ", transport.send: " + typeof(transport.send));
return;
}

var channel = this;
this.transport = transport;

this.send = function(data)
{
if (typeof(data) !== "string") {
data = JSON.stringify(data);
}
channel.transport.send(data);
}

this.transport.onmessage = function(message)
{
var data = message.data;
if (typeof data === "string") {
data = JSON.parse(data);
}
switch (data.type) {
case QWebChannelMessageTypes.signal:
channel.handleSignal(data);
break;
case QWebChannelMessageTypes.response:
channel.handleResponse(data);
break;
case QWebChannelMessageTypes.propertyUpdate:
channel.handlePropertyUpdate(data);
break;
default:
console.error("invalid message received:", message.data);
break;
}
}

this.execCallbacks = {};
this.execId = 0;
this.exec = function(data, callback)
{
if (!callback) {
// if no callback is given, send directly
channel.send(data);
return;
}
if (channel.execId === Number.MAX_VALUE) {
// wrap
channel.execId = Number.MIN_VALUE;
}
if (data.hasOwnProperty("id")) {
console.error("Cannot exec message with property id: " + JSON.stringify(data));
return;
}
data.id = channel.execId++;
channel.execCallbacks[data.id] = callback;
channel.send(data);
};

this.objects = {};

this.handleSignal = function(message)
{
var object = channel.objects[message.object];
if (object) {
object.signalEmitted(message.signal, message.args);
} else {
console.warn("Unhandled signal: " + message.object + "::" + message.signal);
}
}

this.handleResponse = function(message)
{
if (!message.hasOwnProperty("id")) {
console.error("Invalid response message received: ", JSON.stringify(message));
return;
}
channel.execCallbacks[message.id](message.data);
delete channel.execCallbacks[message.id];
}

this.handlePropertyUpdate = function(message)
{
for (var i in message.data) {
var data = message.data[i];
var object = channel.objects[data.object];
if (object) {
object.propertyUpdate(data.signals, data.properties);
} else {
console.warn("Unhandled property update: " + data.object + "::" + data.signal);
}
}
channel.exec({type: QWebChannelMessageTypes.idle});
}

this.debug = function(message)
{
channel.send({type: QWebChannelMessageTypes.debug, data: message});
};

channel.exec({type: QWebChannelMessageTypes.init}, function(data) {
for (var objectName in data) {
var object = new QObject(objectName, data[objectName], channel);
}
// now unwrap properties, which might reference other registered objects
for (var objectName in channel.objects) {
channel.objects[objectName].unwrapProperties();
}
if (initCallback) {
initCallback(channel);
}
channel.exec({type: QWebChannelMessageTypes.idle});
});
};

function QObject(name, data, webChannel)
{
this.__id__ = name;
webChannel.objects[name] = this;

// List of callbacks that get invoked upon signal emission
this.__objectSignals__ = {};

// Cache of all properties, updated when a notify signal is emitted
this.__propertyCache__ = {};

var object = this;

// ----------------------------------------------------------------------

this.unwrapQObject = function(response)
{
if (response instanceof Array) {
// support list of objects
var ret = new Array(response.length);
for (var i = 0; i < response.length; ++i) {
ret[i] = object.unwrapQObject(response[i]);
}
return ret;
}
if (!response
|| !response["__QObject*__"]
|| response.id === undefined) {
return response;
}

var objectId = response.id;
if (webChannel.objects[objectId])
return webChannel.objects[objectId];

if (!response.data) {
console.error("Cannot unwrap unknown QObject " + objectId + " without data.");
return;
}

var qObject = new QObject( objectId, response.data, webChannel );
qObject.destroyed.connect(function() {
if (webChannel.objects[objectId] === qObject) {
delete webChannel.objects[objectId];
// reset the now deleted QObject to an empty {} object
// just assigning {} though would not have the desired effect, but the
// below also ensures all external references will see the empty map
// NOTE: this detour is necessary to workaround QTBUG-40021
var propertyNames = [];
for (var propertyName in qObject) {
propertyNames.push(propertyName);
}
for (var idx in propertyNames) {
delete qObject[propertyNames[idx]];
}
}
});
// here we are already initialized, and thus must directly unwrap the properties
qObject.unwrapProperties();
return qObject;
}

this.unwrapProperties = function()
{
for (var propertyIdx in object.__propertyCache__) {
object.__propertyCache__[propertyIdx] = object.unwrapQObject(object.__propertyCache__[propertyIdx]);
}
}

function addSignal(signalData, isPropertyNotifySignal)
{
var signalName = signalData[0];
var signalIndex = signalData[1];
object[signalName] = {
connect: function(callback) {
if (typeof(callback) !== "function") {
console.error("Bad callback given to connect to signal " + signalName);
return;
}

object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || [];
object.__objectSignals__[signalIndex].push(callback);

if (!isPropertyNotifySignal && signalName !== "destroyed") {
// only required for "pure" signals, handled separately for properties in propertyUpdate
// also note that we always get notified about the destroyed signal
webChannel.exec({
type: QWebChannelMessageTypes.connectToSignal,
object: object.__id__,
signal: signalIndex
});
}
},
disconnect: function(callback) {
if (typeof(callback) !== "function") {
console.error("Bad callback given to disconnect from signal " + signalName);
return;
}
object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || [];
var idx = object.__objectSignals__[signalIndex].indexOf(callback);
if (idx === -1) {
console.error("Cannot find connection of signal " + signalName + " to " + callback.name);
return;
}
object.__objectSignals__[signalIndex].splice(idx, 1);
if (!isPropertyNotifySignal && object.__objectSignals__[signalIndex].length === 0) {
// only required for "pure" signals, handled separately for properties in propertyUpdate
webChannel.exec({
type: QWebChannelMessageTypes.disconnectFromSignal,
object: object.__id__,
signal: signalIndex
});
}
}
};
}

/**
* Invokes all callbacks for the given signalname. Also works for property notify callbacks.
*/
function invokeSignalCallbacks(signalName, signalArgs)
{
var connections = object.__objectSignals__[signalName];
if (connections) {
connections.forEach(function(callback) {
callback.apply(callback, signalArgs);
});
}
}

this.propertyUpdate = function(signals, propertyMap)
{
// update property cache
for (var propertyIndex in propertyMap) {
var propertyValue = propertyMap[propertyIndex];
object.__propertyCache__[propertyIndex] = propertyValue;
}

for (var signalName in signals) {
// Invoke all callbacks, as signalEmitted() does not. This ensures the
// property cache is updated before the callbacks are invoked.
invokeSignalCallbacks(signalName, signals[signalName]);
}
}

this.signalEmitted = function(signalName, signalArgs)
{
invokeSignalCallbacks(signalName, signalArgs);
}

function addMethod(methodData)
{
var methodName = methodData[0];
var methodIdx = methodData[1];
object[methodName] = function() {
var args = [];
var callback;
for (var i = 0; i < arguments.length; ++i) {
if (typeof arguments[i] === "function")
callback = arguments[i];
else
args.push(arguments[i]);
}

webChannel.exec({
"type": QWebChannelMessageTypes.invokeMethod,
"object": object.__id__,
"method": methodIdx,
"args": args
}, function(response) {
if (response !== undefined) {
var result = object.unwrapQObject(response);
if (callback) {
(callback)(result);
}
}
});
};
}

function bindGetterSetter(propertyInfo)
{
var propertyIndex = propertyInfo[0];
var propertyName = propertyInfo[1];
var notifySignalData = propertyInfo[2];
// initialize property cache with current value
// NOTE: if this is an object, it is not directly unwrapped as it might
// reference other QObject that we do not know yet
object.__propertyCache__[propertyIndex] = propertyInfo[3];

if (notifySignalData) {
if (notifySignalData[0] === 1) {
// signal name is optimized away, reconstruct the actual name
notifySignalData[0] = propertyName + "Changed";
}
addSignal(notifySignalData, true);
}

Object.defineProperty(object, propertyName, {
configurable: true,
get: function () {
var propertyValue = object.__propertyCache__[propertyIndex];
if (propertyValue === undefined) {
// This shouldn't happen
console.warn("Undefined value in property cache for property \"" + propertyName + "\" in object " + object.__id__);
}

return propertyValue;
},
set: function(value) {
if (value === undefined) {
console.warn("Property setter for " + propertyName + " called with undefined value!");
return;
}
object.__propertyCache__[propertyIndex] = value;
webChannel.exec({
"type": QWebChannelMessageTypes.setProperty,
"object": object.__id__,
"property": propertyIndex,
"value": value
});
}
});

}

// ----------------------------------------------------------------------

data.methods.forEach(addMethod);

data.properties.forEach(bindGetterSetter);

data.signals.forEach(function(signal) { addSignal(signal, false); });

for (var name in data.enums) {
object[name] = data.enums[name];
}
}

//required for use with nodejs
if (typeof module === 'object') {
module.exports = {
QWebChannel: QWebChannel
};
}

2、Z01.html

<!DOCTYPE html>

<html>
<head>
<meta charset="UTF-8">

<script type="text/javascript" >
<!--

window.onload = function()
{
};

-->
</script>

</head>

<body>

<ahref="javascript:document.getElementByIdx_x("myLabel").setText("通过JavaScript访问Qt对象");"mce_href="javascript:document.getElementByIdx_x("myLabel").setText("通过JavaScript访问Qt对象");">点击访问Qt对象</a>

</body>
</html>

3、