I think you should not try to interact with org.freedesktop.DBus interface directly, instead you should use QDBusConnectionInterface for that. In your particular case, this would be using https://doc.qt.io/qt-5/qdbusconnectioninterface.html #registeredServiceNames-prop:
const QDBusConnectionInterface *iface = QDBusConnection::sessionBus().interface(); QDBusReply<QStringList> servicesReply = iface->registeredServiceNames(); qDebug() << servicesReply.value(); Any other interface would work fine, org.freedesktop.dbus is blacklisted here: https://code.qt.io/cgit/qt/qtbase.git/tree/src/dbus/qdbusintegrator.cpp?h=5.9#n2448 ** Changed in: qtbase-opensource-src (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to qtbase-opensource-src in Ubuntu. https://bugs.launchpad.net/bugs/1776446 Title: QDBusInterface is able to connect to org.freedesktop.DBus, but its status is invalid Status in qtbase-opensource-src package in Ubuntu: Invalid Bug description: Consider the following example: #include <QtCore> #include <QtDBus> int main(int argc, char *argv[]) { QCoreApplication app(argc, argv); QDBusInterface dbus("org.freedesktop.DBus", "/org/freedesktop/DBus", "org.freedesktop.DBus", QDBusConnection::sessionBus()); if (!dbus.isValid()) { qDebug() << "IFACE IS NOT VALID" << dbus.lastError().message(); return 1; } QDBusReply<QStringList> servicesReply = dbus.call("ListNames"); if (!servicesReply.isValid()) { qDebug() << "REPLY IS NOT VALID" << servicesReply.error().message(); return 2; } qDebug() << servicesReply.value(); } Compile and run. It prints IFACE IS NOT VALID "" The issue here is that QDBusInterface::isValid() returns false, however it's still possible to call its methods. If I comment out the "if (!dbus.isValid())" line, it starts to work fine: #include <QtCore> #include <QtDBus> int main(int argc, char *argv[]) { QCoreApplication app(argc, argv); QDBusInterface dbus("org.freedesktop.DBus", "/org/freedesktop/DBus", "org.freedesktop.DBus", QDBusConnection::sessionBus()); /* if (!dbus.isValid()) { qDebug() << "IFACE IS NOT VALID" << dbus.lastError().message(); return 1; } */ // WORKS FINE! QDBusReply<QStringList> servicesReply = dbus.call("ListNames"); if (!servicesReply.isValid()) { qDebug() << "REPLY IS NOT VALID" << servicesReply.error().message(); return 2; } qDebug() << servicesReply.value(); } In Ubuntu 16.04 it worked fine. All updates have been installed. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qtbase-opensource-src/+bug/1776446/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
