<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qdbusextratypes.cpp --> <title>QDBusVariant Class | Qt D-Bus</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="qtdbus-index.html">Qt D-Bus</a></td><td ><a href="qtdbus-module.html">C++ Classes</a></td><td >QDBusVariant</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtdbus-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="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">QDBusVariant Class</h1> <!-- $$$QDBusVariant-brief --> <p>The <a href="qdbusvariant.html">QDBusVariant</a> class enables the programmer to identify the variant type provided by the D-Bus typesystem. <a href="#details">More...</a></p> <!-- @@@QDBusVariant --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QDBusVariant></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += dbus</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> Qt 4.2</td></tr></table></div><ul> <li><a href="qdbusvariant-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qdbusvariant.html#QDBusVariant">QDBusVariant</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qdbusvariant.html#QDBusVariant-1">QDBusVariant</a></b>(const QVariant &<i>variant</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qdbusvariant.html#QDBusVariant-2">QDBusVariant</a></b>(QVariant &&<i>v</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qdbusvariant.html#setVariant">setVariant</a></b>(const QVariant &<i>variant</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qdbusvariant.html#swap">swap</a></b>(QDBusVariant &<i>other</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QVariant </td><td class="memItemRight bottomAlign"><b><a href="qdbusvariant.html#variant">variant</a></b>() const</td></tr> </table></div> <a name="details"></a> <!-- $$$QDBusVariant-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qdbusvariant.html">QDBusVariant</a> class enables the programmer to identify the variant type provided by the D-Bus typesystem.</p> <p>A D-Bus function that takes an integer, a D-Bus variant and a string as parameters can be called with the following argument list (see <a href="qdbusmessage.html#setArguments">QDBusMessage::setArguments</a>()):</p> <pre class="cpp"> <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator"><</span><span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span><span class="operator">></span> arguments; arguments <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span>(<span class="number">42</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span><span class="operator">::</span>fromValue(<span class="type"><a href="qdbusvariant.html#QDBusVariant">QDBusVariant</a></span>(<span class="number">43</span>)) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span>(<span class="string">"hello"</span>); myDBusMessage<span class="operator">.</span>setArguments(arguments); </pre> <p>When a D-Bus function returns a D-Bus variant, it can be retrieved as follows:</p> <pre class="cpp"> <span class="comment">// call a D-Bus function that returns a D-Bus variant</span> <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> v <span class="operator">=</span> callMyDBusFunction(); <span class="comment">// retrieve the D-Bus variant</span> <span class="type"><a href="qdbusvariant.html#QDBusVariant">QDBusVariant</a></span> dbusVariant <span class="operator">=</span> qvariant_cast<span class="operator"><</span><span class="type"><a href="qdbusvariant.html#QDBusVariant">QDBusVariant</a></span><span class="operator">></span>(v); <span class="comment">// retrieve the actual value stored in the D-Bus variant</span> <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> result <span class="operator">=</span> dbusVariant<span class="operator">.</span>variant(); </pre> <p>The <a href="../qtcore/qvariant.html">QVariant</a> within a <a href="qdbusvariant.html">QDBusVariant</a> is required to distinguish between a normal D-Bus value and a value within a D-Bus variant.</p> </div> <p><b>See also </b><a href="qdbustypesystem.html">The Qt D-Bus Type System</a>.</p> <!-- @@@QDBusVariant --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QDBusVariant[overload1]$$$QDBusVariant --> <h3 class="fn" id="QDBusVariant"><a name="QDBusVariant"></a>QDBusVariant::<span class="name">QDBusVariant</span>()</h3> <p>Constructs a new D-Bus variant.</p> <!-- @@@QDBusVariant --> <!-- $$$QDBusVariant$$$QDBusVariantconstQVariant& --> <h3 class="fn" id="QDBusVariant-1"><a name="QDBusVariant-1"></a>QDBusVariant::<span class="name">QDBusVariant</span>(const <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> &<i>variant</i>)</h3> <p>Constructs a new D-Bus variant from the given Qt <i>variant</i>.</p> <p><b>See also </b><a href="qdbusvariant.html#setVariant">setVariant</a>().</p> <!-- @@@QDBusVariant --> <!-- $$$QDBusVariant$$$QDBusVariantQVariant&& --> <h3 class="fn" id="QDBusVariant-2"><a name="QDBusVariant-2"></a>QDBusVariant::<span class="name">QDBusVariant</span>(<span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> &&<i>v</i>)</h3> <p>Default constructs an instance of QDBusVariant.</p><!-- @@@QDBusVariant --> <!-- $$$setVariant[overload1]$$$setVariantconstQVariant& --> <h3 class="fn" id="setVariant"><a name="setVariant"></a><span class="type">void</span> QDBusVariant::<span class="name">setVariant</span>(const <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> &<i>variant</i>)</h3> <p>Assigns the value of the given Qt <i>variant</i> to this D-Bus variant.</p> <p><b>See also </b><a href="qdbusvariant.html#variant">variant</a>().</p> <!-- @@@setVariant --> <!-- $$$swap[overload1]$$$swapQDBusVariant& --> <h3 class="fn" id="swap"><a name="swap"></a><span class="type">void</span> QDBusVariant::<span class="name">swap</span>(<span class="type"><a href="qdbusvariant.html#QDBusVariant">QDBusVariant</a></span> &<i>other</i>)</h3> <p>Swaps this <a href="qdbusvariant.html">QDBusVariant</a> instance with <i>other</i>.</p> <!-- @@@swap --> <!-- $$$variant[overload1]$$$variant --> <h3 class="fn" id="variant"><a name="variant"></a><span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> QDBusVariant::<span class="name">variant</span>() const</h3> <p>Returns this D-Bus variant as a <a href="../qtcore/qvariant.html">QVariant</a> object.</p> <p><b>See also </b><a href="qdbusvariant.html#setVariant">setVariant</a>().</p> <!-- @@@variant --> </div> </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>