ukui-search/3rd-parties/qtsingleapplication/doc/html/qtsinglecoreapplication-exa...

119 lines
5.3 KiB
HTML
Raw Normal View History

2023-08-15 17:34:41 +08:00
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<!-- console.qdoc -->
<head>
<title>A non-GUI example</title>
<link href="classic.css" rel="stylesheet" type="text/css" />
</head>
<body>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr>
<td align="left" valign="top" width="32"><img src="images/qt-logo.png" align="left" width="57" height="67" border="0" /></td>
<td width="1">&nbsp;&nbsp;</td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a></td>
</tr></table><h1 class="title">A non-GUI example<br /><span class="subtitle"></span>
</h1>
<p>This example shows how to use the single-application functionality in a console application. It does not require the <tt>QtGui</tt> library at all.</p>
<p>The only differences from the GUI application usage demonstrated in the other examples are:</p>
<p>1) The <tt>.pro</tt> file should include <tt>qtsinglecoreapplication.pri</tt> instead of <tt>qtsingleapplication.pri</tt></p>
<p>2) The class name is <tt>QtSingleCoreApplication</tt> instead of <tt>QtSingleApplication</tt>.</p>
<p>3) No calls are made regarding window activation, for obvious reasons.</p>
<p>console.pro:</p>
<pre> TEMPLATE = app
CONFIG += console
SOURCES += main.cpp
include(../../src/qtsinglecoreapplication.pri)
QT -= gui</pre>
<p>main.cpp:</p>
<pre><span class="comment"> /****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Solutions component.
**
** You may use this file under the terms of the BSD license as follows:
**
** &quot;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 Nokia Corporation 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
** &quot;AS IS&quot; 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.&quot;
**
****************************************************************************/</span>
#include &quot;qtsinglecoreapplication.h&quot;
#include &lt;QtCore/QDebug&gt;
void report(const QString&amp; msg)
{
qDebug(&quot;[%i] %s&quot;, (int)QCoreApplication::applicationPid(), qPrintable(msg));
}
class MainClass : public QObject
{
Q_OBJECT
public:
MainClass()
: QObject()
{}
public slots:
void handleMessage(const QString&amp; message)
{
report( &quot;Message received: \&quot;&quot; + message + &quot;\&quot;&quot;);
}
};
int main(int argc, char **argv)
{
report(&quot;Starting up&quot;);
QtSingleCoreApplication app(argc, argv);
if (app.isRunning()) {
QString msg(QString(&quot;Hi master, I am %1.&quot;).arg(QCoreApplication::applicationPid()));
bool sentok = app.sendMessage(msg, 2000);
QString rep(&quot;Another instance is running, so I will exit.&quot;);
rep += sentok ? &quot; Message sent ok.&quot; : &quot; Message sending failed; the other instance may be frozen.&quot;;
report(rep);
return 0;
} else {
report(&quot;No other instance is running; so I will.&quot;);
MainClass mainObj;
QObject::connect(&amp;app, SIGNAL(messageReceived(const QString&amp;)),
&amp;mainObj, SLOT(handleMessage(const QString&amp;)));
return app.exec();
}
}
#include &quot;main.moc&quot;</pre>
<p /><address><hr /><div align="center">
<table width="100%" cellspacing="0" border="0"><tr class="address">
<td width="30%" align="left">Copyright &copy; 2010 Nokia Corporation and/or its subsidiary(-ies)</td>
<td width="40%" align="center"><a href="http://qt.nokia.com/doc/trademarks.html">Trademarks</a></td>
<td width="30%" align="right"><div align="right">Qt Solutions</div></td>
</tr></table></div></address></body>
</html>