- Qt 5.15
- Qt D-Bus
- C++ Classes
- QDBusVariant
- Qt 5.15.18 Reference Documentation

# QDBusVariant Class

The QDBusVariant class enables the programmer to identify the variant type provided by the D-Bus typesystem. More...

Header: | #include <QDBusVariant>
qmake: | QT += dbus
Since: | Qt 4.2

This class was introduced in Qt 4.2.

- List of all members, including inherited members

## Public Functions

| QDBusVariant(const QVariant &variant)
| QDBusVariant()
void | setVariant(const QVariant &variant)
void | swap(QDBusVariant &other)
QVariant | variant() const

## Detailed Description

A D-Bus function that takes an integer, a D-Bus variant and a string as parameters can be called with the following argument list (see QDBusMessage::setArguments()):

         QList<QVariant> arguments;
         arguments << QVariant(42) << QVariant::fromValue(QDBusVariant(43)) << QVariant("hello");
         myDBusMessage.setArguments(arguments);

When a D-Bus function returns a D-Bus variant, it can be retrieved as follows:

         // call a D-Bus function that returns a D-Bus variant
         QVariant v = callMyDBusFunction();
         // retrieve the D-Bus variant
         QDBusVariant dbusVariant = qvariant_cast<QDBusVariant>(v);
         // retrieve the actual value stored in the D-Bus variant
         QVariant result = dbusVariant.variant();

The QVariant within a QDBusVariant is required to distinguish between a normal D-Bus value and a value within a D-Bus variant.

See also The Qt D-Bus Type System.

## Member Function Documentation

### QDBusVariant::QDBusVariant(const QVariant &variant)

Constructs a new D-Bus variant from the given Qt variant.

See also setVariant().

### QDBusVariant::QDBusVariant()

Constructs a new D-Bus variant.

### void QDBusVariant::setVariant(const QVariant &variant)

Assigns the value of the given Qt variant to this D-Bus variant.

See also variant().

### void QDBusVariant::swap(QDBusVariant &other)

Swaps this QDBusVariant instance with other.

### QVariant QDBusVariant::variant() const

Returns this D-Bus variant as a QVariant object.

See also setVariant().