QT原始碼閱讀——QT與HTML互動程式設計
阿新 • • 發佈:2019-01-23
QT中通過QWebKit元件處理HTML,其中最重要的就是QWebView了~~~
通過例子formextractor我們可以窺之一二:
/**************************************************************************** ** ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). ** Contact: http://www.qt-project.org/legal ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 Digia Plc and its Subsidiary(-ies) 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, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> #include "formextractor.h" QT_BEGIN_NAMESPACE class QAction; class QMenu; QT_END_NAMESPACE class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(); private slots: void about(); private: FormExtractor *centralWidget; QMenu *fileMenu; QMenu *helpMenu; QAction *exitAct; QAction *aboutAct; QAction *aboutQtAct; void createActions(); void createMenus(); }; #endif // MAINWINDOW_H
/**************************************************************************** ** ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). ** Contact: http://www.qt-project.org/legal ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 Digia Plc and its Subsidiary(-ies) 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, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (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 <QtWidgets> #include "mainwindow.h" MainWindow::MainWindow() { createActions(); createMenus(); centralWidget = new FormExtractor(this); setCentralWidget(centralWidget); setUnifiedTitleAndToolBarOnMac(true); } void MainWindow::createActions() { exitAct = new QAction(tr("E&xit"), this); exitAct->setStatusTip(tr("Exit the application")); exitAct->setShortcuts(QKeySequence::Quit); connect(exitAct, SIGNAL(triggered()), this, SLOT(close())); aboutAct = new QAction(tr("&About"), this); aboutAct->setStatusTip(tr("Show the application's About box")); connect(aboutAct, SIGNAL(triggered()), this, SLOT(about())); aboutQtAct = new QAction(tr("About &Qt"), this); aboutQtAct->setStatusTip(tr("Show the Qt library's About box")); connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt())); } void MainWindow::createMenus() { fileMenu = menuBar()->addMenu(tr("&File")); fileMenu->addAction(exitAct); menuBar()->addSeparator(); helpMenu = menuBar()->addMenu(tr("&Help")); helpMenu->addAction(aboutAct); helpMenu->addAction(aboutQtAct); } void MainWindow::about() { QMessageBox::about(this, tr("About Form Extractor"), tr("The <b>Form Extractor</b> example demonstrates how to " "extract data from a web form using QtWebKit.")); }
核心互動類:
/**************************************************************************** ** ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). ** Contact: http://www.qt-project.org/legal ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 Digia Plc and its Subsidiary(-ies) 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, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #ifndef FORMEXTRACTOR_H #define FORMEXTRACTOR_H #include <QtWidgets/QWidget> #include <QWebFrame> #include "ui_formextractor.h" class FormExtractor : public QWidget { Q_OBJECT public: FormExtractor(QWidget *parent = 0, Qt::WindowFlags flags = 0); ~FormExtractor(); public slots: void submit(); void populateJavaScriptWindowObject(); private: Ui::Form ui; }; #endif // FORMEXTRACTOR_H
/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 Digia Plc and its Subsidiary(-ies) 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,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (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 "formextractor.h"
#include <QWebElement>
FormExtractor::FormExtractor(QWidget *parent, Qt::WindowFlags flags)
: QWidget(parent, flags)
{
ui.setupUi(this);
ui.webView->setUrl(QUrl("qrc:/form.html"));
connect(ui.webView->page()->mainFrame(), SIGNAL(javaScriptWindowObjectCleared()),
this, SLOT(populateJavaScriptWindowObject()));
resize(300, 300);
}
FormExtractor::~FormExtractor()
{
}
void FormExtractor::submit()
{
QWebFrame *frame = ui.webView->page()->mainFrame();
QWebElement firstName = frame->findFirstElement("#firstname");
QWebElement lastName = frame->findFirstElement("#lastname");
QWebElement maleGender = frame->findFirstElement("#genderMale");
QWebElement femaleGender = frame->findFirstElement("#genderFemale");
QWebElement updates = frame->findFirstElement("#updates");
ui.firstNameEdit->setText(firstName.evaluateJavaScript("this.value").toString());
ui.lastNameEdit->setText(lastName.evaluateJavaScript("this.value").toString());
if (maleGender.evaluateJavaScript("this.checked").toBool())
ui.genderEdit->setText(maleGender.evaluateJavaScript("this.value").toString());
else if (femaleGender.evaluateJavaScript("this.checked").toBool())
ui.genderEdit->setText(femaleGender.evaluateJavaScript("this.value").toString());
if (updates.evaluateJavaScript("this.checked").toBool())
ui.updatesEdit->setText("Yes");
else
ui.updatesEdit->setText("No");
}
void FormExtractor::populateJavaScriptWindowObject()
{
ui.webView->page()->mainFrame()->addToJavaScriptWindowObject("formExtractor", this);
}
HTML頁面:
<html><body>
<h1>
The Green People Book Club
</h1>
<p>
Welcome to The Green People Book Club. Please register to obtain a membership with us.
</p>
<form onsubmit="formExtractor.submit()">
<table>
<tbody><tr>
<td>
First name:
</td>
<td>
<input type="text" id="firstname">
</td>
</tr>
<tr>
<td>
Last name:
</td>
<td>
<input type="text" id="lastname">
</td>
</tr>
<tr>
<td>
Gender:
</td>
<td>
<input type="radio" name="gender" id="genderMale" value="Male"> Male
<input type="radio" name="gender" id="genderFemale" value="Female"> Female
</td>
</tr>
<tr>
<td colspan="2">
<input type="checkbox" id="updates" value="receive">
Check here if you would like to receive regular updates from us:
</td>
</tr>
</tbody></table>
<input type="submit" value="Submit">
</form>
</body></html>
其中關鍵就是:
<form onsubmit="formExtractor.submit()">
ui.webView->page()->mainFrame()->addToJavaScriptWindowObject("formExtractor", this);
void QWebFrame::addToJavaScriptWindowObject(const QString & name, QObject * object, ValueOwnership own = QtOwnership);
作用就是講處理物件object作為html的window物件的javascript子物件,這樣就相當於在html頁面中添加了相應的javascript處理函式,實現了互動功能!