class MyObject: public QObject,
                protected QDBusContext
{
    Q_OBJECT
    QDBusConnection conn;
    QDBusMessage msg;

...

protected slots:
    void process();
public slots:
    void methodWithError();
    QString methodWithDelayedReply();
};

void MyObject::methodWithError()
{
    sendErrorReply(QDBusError::NotSupported,
                   "The method call 'methodWithError()' is not supported");
}

QString MyObject::methodWithDelayedReply()
{
    conn = connection();
    msg = message();
    setDelayedReply(true);
    QMetaObject::invokeMethod(this, "process", Qt::QueuedConnection);
    return QString();
}

Member Function Documentation

QDBusContext::QDBusContext()

Constructs an empty QDBusContext.

QDBusContext::~QDBusContext()

An empty destructor.

bool QDBusContext::calledFromDBus() const

Returns true if we are processing a D-Bus call. If this function returns true, the rest of the functions in this class are available.

Accessing those functions when this function returns false is undefined and may lead to crashes.

QDBusConnection QDBusContext::connection() const

Returns the connection from which this call was received.

bool QDBusContext::isDelayedReply() const

Returns true if this call will have a delayed reply.

See also setDelayedReply().

const QDBusMessage &QDBusContext::message() const

Returns the message that generated this call.

void QDBusContext::sendErrorReply(const QString &name, const QString &msg = QString()) const

Sends an error name as a reply to the caller. The optional msg parameter is a human-readable text explaining the failure.

If an error is sent, the return value and any output parameters from the called slot will be ignored by Qt D-Bus.

void QDBusContext::sendErrorReply(QDBusError::ErrorType type, const QString &msg = QString()) const

This is an overloaded function.

Sends an error type as a reply to the caller. The optional msg parameter is a human-readable text explaining the failure.

If an error is sent, the return value and any output parameters from the called slot will be ignored by Qt D-Bus.

void QDBusContext::setDelayedReply(bool enable) const

Sets whether this call will have a delayed reply or not.

If enable is false, Qt D-Bus will automatically generate a reply back to the caller, if needed, as soon as the called slot returns.

If enable is true, Qt D-Bus will not generate automatic replies. It will also ignore the return value from the slot and any output parameters. Instead, the called object is responsible for storing the incoming message and send a reply or error at a later time.

Failing to send a reply will result in an automatic timeout error being generated by D-Bus.

See also isDelayedReply().