<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>main.cpp Example File | Qt Concurrent 5.12.6</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtconcurrent-index.html">Qt Concurrent</a></td><td ><a href="qtconcurrent-progressdialog-example.html">QtConcurrent Progress Dialog Example</a></td><td >main.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtconcurrent-index.html">Qt 5.12.6 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">main.cpp Example File</h1> <span class="subtitle">progressdialog/main.cpp</span> <!-- $$$progressdialog/main.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples 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, ** 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." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include <QtWidgets></span> <span class="preprocessor">#include <QtConcurrent></span> <span class="preprocessor">#include <functional></span> <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="type"><a href="qtconcurrent-module.html">QtConcurrent</a></span>; <span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span> <span class="operator">*</span><span class="operator">*</span>argv) { <span class="type">QApplication</span> app(argc<span class="operator">,</span> argv); <span class="keyword">const</span> <span class="type">int</span> iterations <span class="operator">=</span> <span class="number">20</span>; <span class="comment">// Prepare the vector.</span> <span class="type"><a href="../qtcore/qvector.html">QVector</a></span><span class="operator"><</span><span class="type">int</span><span class="operator">></span> vector; <span class="keyword">for</span> (<span class="type">int</span> i <span class="operator">=</span> <span class="number">0</span>; i <span class="operator"><</span> iterations; <span class="operator">+</span><span class="operator">+</span>i) vector<span class="operator">.</span>append(i); <span class="comment">// Create a progress dialog.</span> <span class="type">QProgressDialog</span> dialog; dialog<span class="operator">.</span>setLabelText(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>(<span class="string">"Progressing using %1 thread(s)..."</span>)<span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qthread.html">QThread</a></span><span class="operator">::</span>idealThreadCount())); <span class="comment">// Create a QFutureWatcher and connect signals and slots.</span> <span class="type"><a href="../qtcore/qfuturewatcher.html">QFutureWatcher</a></span><span class="operator"><</span><span class="type">void</span><span class="operator">></span> futureWatcher; <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="operator">&</span>futureWatcher<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qfuturewatcher.html">QFutureWatcher</a></span><span class="operator"><</span><span class="type">void</span><span class="operator">></span><span class="operator">::</span>finished<span class="operator">,</span> <span class="operator">&</span>dialog<span class="operator">,</span> <span class="operator">&</span><span class="type">QProgressDialog</span><span class="operator">::</span>reset); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="operator">&</span>dialog<span class="operator">,</span> <span class="operator">&</span><span class="type">QProgressDialog</span><span class="operator">::</span>canceled<span class="operator">,</span> <span class="operator">&</span>futureWatcher<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qfuturewatcher.html">QFutureWatcher</a></span><span class="operator"><</span><span class="type">void</span><span class="operator">></span><span class="operator">::</span>cancel); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="operator">&</span>futureWatcher<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qfuturewatcher.html">QFutureWatcher</a></span><span class="operator"><</span><span class="type">void</span><span class="operator">></span><span class="operator">::</span>progressRangeChanged<span class="operator">,</span> <span class="operator">&</span>dialog<span class="operator">,</span> <span class="operator">&</span><span class="type">QProgressDialog</span><span class="operator">::</span>setRange); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="operator">&</span>futureWatcher<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qfuturewatcher.html">QFutureWatcher</a></span><span class="operator"><</span><span class="type">void</span><span class="operator">></span><span class="operator">::</span>progressValueChanged<span class="operator">,</span> <span class="operator">&</span>dialog<span class="operator">,</span> <span class="operator">&</span><span class="type">QProgressDialog</span><span class="operator">::</span>setValue); <span class="comment">// Our function to compute</span> std<span class="operator">::</span>function<span class="operator"><</span><span class="type">void</span>(<span class="type">int</span><span class="operator">&</span>)<span class="operator">></span> spin <span class="operator">=</span> <span class="operator">[</span><span class="operator">]</span>(<span class="type">int</span> <span class="operator">&</span>iteration) { <span class="keyword">const</span> <span class="type">int</span> work <span class="operator">=</span> <span class="number">1000</span> <span class="operator">*</span> <span class="number">1000</span> <span class="operator">*</span> <span class="number">40</span>; <span class="keyword">volatile</span> <span class="type">int</span> v <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">for</span> (<span class="type">int</span> j <span class="operator">=</span> <span class="number">0</span>; j <span class="operator"><</span> work; <span class="operator">+</span><span class="operator">+</span>j) <span class="operator">+</span><span class="operator">+</span>v; <a href="../qtcore/qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"iteration"</span> <span class="operator"><</span><span class="operator"><</span> iteration <span class="operator"><</span><span class="operator"><</span> <span class="string">"in thread"</span> <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtcore/qthread.html">QThread</a></span><span class="operator">::</span>currentThreadId(); }; <span class="comment">// Start the computation.</span> futureWatcher<span class="operator">.</span>setFuture(<span class="type"><a href="qtconcurrent-module.html">QtConcurrent</a></span><span class="operator">::</span>map(vector<span class="operator">,</span> spin)); <span class="comment">// Display the dialog and start the event loop.</span> dialog<span class="operator">.</span>exec(); futureWatcher<span class="operator">.</span>waitForFinished(); <span class="comment">// Query the future to check if was canceled.</span> <a href="../qtcore/qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Canceled?"</span> <span class="operator"><</span><span class="operator"><</span> futureWatcher<span class="operator">.</span>future()<span class="operator">.</span>isCanceled(); } </pre> </div> <!-- @@@progressdialog/main.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>