<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qdeclarativenearfield.cpp --> <title>NearField QML Type | Qt NFC 5.12.2</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="qtnfc-index.html">Qt NFC</a></td><td ><a href="qtnfc-qmlmodule.html">QML Types</a></td><td >NearField QML Type</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtnfc-index.html">Qt 5.12.2 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="#properties">Properties</a></li> <li class="level1"><a href="#signals">Signals</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">NearField QML Type</h1> <span class="subtitle"></span> <!-- $$$NearField-brief --> <p>Provides access to NDEF messages stored on NFC Forum tags. <a href="#details">More...</a></p> <!-- @@@NearField --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Import Statement:</td><td class="memItemRight bottomAlign"> import QtNfc 5.12</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> Qt 5.2</td></tr></table></div><ul> <li><a href="qml-qtnfc-nearfield-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2 id="properties">Properties</h2> <ul> <li class="fn"><b><b><a href="qml-qtnfc-nearfield.html#filter-prop">filter</a></b></b> : list<NdefFilter></li> <li class="fn"><b><b><a href="qml-qtnfc-nearfield.html#messageRecords-prop">messageRecords</a></b></b> : list<NdefRecord></li> <li class="fn"><b><b><a href="qml-qtnfc-nearfield.html#orderMatch-prop">orderMatch</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-qtnfc-nearfield.html#polling-prop">polling</a></b></b> : bool</li> </ul> <a name="signals"></a> <h2 id="signals">Signals</h2> <ul> <li class="fn"><b><b><a href="qml-qtnfc-nearfield.html#tagFound-signal">tagFound</a></b></b>()</li> <li class="fn"><b><b><a href="qml-qtnfc-nearfield.html#tagRemoved-signal">tagRemoved</a></b></b>()</li> </ul> <!-- $$$NearField-description --> <a name="details"></a> <h2 id="details">Detailed Description</h2> <p>The <a href="qml-qtnfc-nearfield.html">NearField</a> type can be used to read NDEF messages from NFC Forum tags. Set the <a href="qml-qtnfc-nearfield.html#filter-prop">filter</a> and <a href="qml-qtnfc-nearfield.html#orderMatch-prop">orderMatch</a> properties to match the required NDEF messages. Once an NDEF message is successfully read from a tag the <a href="qml-qtnfc-nearfield.html#messageRecords-prop">messageRecords</a> property is updated.</p> <p><b>Note: </b>For platforms using neard, filtering is currently not implemented. For more information on neard see <a href="qnearfieldmanager.html">QNearFieldManager</a>.</p><pre class="qml"> NearField { filter: [ NdefFilter { type: "U"; typeNameFormat: NdefRecord.NfcRtd; minimum: 1; maximum: 1 } ] orderMatch: false onMessageRecordsChanged: displayMessage() } </pre> <p><b>See also </b><a href="qml-qtnfc-ndeffilter.html">NdefFilter</a>, <a href="qml-qtnfc-ndefrecord.html">NdefRecord</a>, <a href="qnearfieldmanager.html">QNearFieldManager</a>, <a href="qndefmessage.html">QNdefMessage</a>, and <a href="qndefrecord.html">QNdefRecord</a>.</p> <!-- @@@NearField --> <h2>Property Documentation</h2> <!-- $$$filter --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="filter-prop"> <td class="tblQmlPropNode"><p> <a name="filter-prop"></a><span class="name">filter</span> : <span class="type">list</span><<span class="type"><a href="qml-qtnfc-ndeffilter.html">NdefFilter</a></span>></p></td></tr> </table></div> </div><div class="qmldoc"><p>This property holds the NDEF filter constraints. The <a href="qml-qtnfc-nearfield.html#messageRecords-prop">messageRecords</a> property will only be set to NDEF messages which match the filter. If no filter is set, a message handler for all NDEF messages will be registered.</p> <p><b>Note: </b>Filtering is not supported when using neard.</p><p><a href="qnearfieldmanager.html#registerNdefMessageHandler">QNearFieldManager::registerNdefMessageHandler()</a></p> </div></div><!-- @@@filter --> <br/> <!-- $$$messageRecords --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="messageRecords-prop"> <td class="tblQmlPropNode"><p> <a name="messageRecords-prop"></a><span class="name">messageRecords</span> : <span class="type">list</span><<span class="type"><a href="qml-qtnfc-ndefrecord.html">NdefRecord</a></span>></p></td></tr> </table></div> </div><div class="qmldoc"><p>This property contains the list of NDEF records in the last NDEF message read.</p> </div></div><!-- @@@messageRecords --> <br/> <!-- $$$orderMatch --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="orderMatch-prop"> <td class="tblQmlPropNode"><p> <a name="orderMatch-prop"></a><span class="name">orderMatch</span> : <span class="type">bool</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>This property indicates whether the order of records should be taken into account when matching messages. This is not supported when using neard.</p> <p>The default of orderMatch is false.</p> </div></div><!-- @@@orderMatch --> <br/> <!-- $$$polling --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="polling-prop"> <td class="tblQmlPropNode"><p> <a name="polling-prop"></a><span class="name">polling</span> : <span class="type">bool</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>This property indicates if the underlying adapter is currently in polling state. If set to <code>true</code> the adapter will start polling and stop polling if set to <code>false</code>.</p> <p><b>Note: </b>On platforms using neard, the adapter will stop polling as soon as a tag has been detected. For more information see <a href="qnearfieldmanager.html">QNearFieldManager</a>.</p><p>This property was introduced in Qt 5.5.</p> </div></div><!-- @@@polling --> <br/> <h2>Signal Documentation</h2> <!-- $$$tagFound --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="tagFound-signal"> <td class="tblQmlFuncNode"><p> <a name="tagFound-signal"></a><span class="name">tagFound</span>()</p></td></tr> </table></div> </div><div class="qmldoc"><p>This signal will be emitted when a tag has been detected.</p> <p>This signal was introduced in Qt 5.5.</p> </div></div><!-- @@@tagFound --> <br/> <!-- $$$tagRemoved --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="tagRemoved-signal"> <td class="tblQmlFuncNode"><p> <a name="tagRemoved-signal"></a><span class="name">tagRemoved</span>()</p></td></tr> </table></div> </div><div class="qmldoc"><p>This signal will be emitted when a tag has been removed.</p> <p>This signal was introduced in Qt 5.5.</p> </div></div><!-- @@@tagRemoved --> <br/> </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>