Why does QDBus complains about wrong type?-CodePudding

What's wrong with the following snippet? I am constantly getting the error

Unexpected reply signature: got "a{sa{sv}}", expected "" (QMap<QString,QVariantMap>)

QDBusInterface connIface(
                    NM_DBUS_SERVICE,
                    "/org/freedesktop/NetworkManager/Settings/1",
                    NM_DBUS_INTERFACE_SETTINGS_CONNECTION,
                    QDBusConnection::systemBus());

QDBusReply<QMap<QString, QMap<QString, QVariant>> > settingsResult = connIface.call("GetSettings");

I really don't get it, seems to be perfectly fine to me. Is it possible that this has to do with the compiler / header-versions somehow?

CodePudding user response：

You have to register the expected Response first!

In my case it was like

#include <QtDBus/QDBusMetaType>
// ...
typedef QMap<QString, QMap<QString, QVariant> > ConnectionDetails;
Q_DECLARE_METATYPE(ConnectionDetails)

and

int main() {
    qDBusRegisterMetaType<ConnectionDetails>();
    // ...
}