Hi all, I am using s signal slot communication for cpp and qml interaction. but when i emit a signal from cpp class i am not able to catch that in Qml...can anyone guide me in this matter... the code is as follows... thanks. my .h code #ifndef HANDLETEXTFIELD_H #define HANDLETEXTFIELD_H #include <QObject> #include <QDebug> class HandleTextField : public QObject { Q_OBJECT public: explicit HandleTextField(QObject *parent = 0); signals: void setTextField(); public slots: Q_INVOKABLE void handleSubmitTextField(); }; #endif // HANDLETEXTFIELD_H my .cpp code #include "handletextfield.h" HandleTextField::HandleTextField(QObject *parent) : QObject(parent) { } void HandleTextField::handleSubmitTextField() { qDebug() << "c++: HandleTextField::handleSubmitTextField:" << endl; emit setTextField(); } my main.cpp #include <QGuiApplication> #include <QQmlApplicationEngine> #include <QQuickWindow> #include <QQmlContext> #include "handletextfield.h" int main(int argc, char *argv[]) { QGuiApplication app(argc, argv); qmlRegisterType<HandleTextField>("com.handletextfield",1,0,"HandleTextField"); QQmlApplicationEngine engine; engine.load(QUrl(QStringLiteral("qrc:/main.qml"))); HandleTextField handleTextField; QObject *topLevel = engine.rootObjects().value(0); QQuickWindow *window = qobject_cast<QQuickWindow *>(topLevel); // QObject::connect(window, SIGNAL(submitTextField(QString)), // &handleTextField, SLOT(handleSubmitTextField(QString))); QObject::connect(&handleTextField, SIGNAL(setTextField()), window, SLOT(setTextField())); return app.exec(); } my qml.main code import QtQuick 2.3 import QtQuick.Window 2.2 import QtQuick.Controls 1.2 import com.handletextfield 1.0 Window { visible: true width: 360 height: 360 HandleTextField { id: testsignal } MouseArea { anchors.fill: parent onClicked: { testsignal.handleSubmitTextField() } } function setTextField(){ console.log("setTextField signal: catched ") } }

QQuick creates signal handlers for your cpp classes like: HandleTextField { id: testsignal onSetTextField: { //your code} } http://doc.qt.io/qt-5/qtqml-cppintegration-exposecppattributes.html#exposing-signals

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How to catch a signal emitted from cpp class in Qml ?

Unsolved QML and Qt Quick

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Naveen_D

wrote on 14 Dec 2016, 11:11 last edited by

#21

Hello, can anyone please help me out with this...
thanks
Naveen_D
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14 Dec 2016, 11:11