QtMobility Reference Documentation

QBluetoothServiceDiscoveryAgent Class Reference

The QBluetoothServiceDiscoveryAgent class provides an API for querying the services provided by a Bluetooth device. More...

 #include <QBluetoothServiceDiscoveryAgent>

Inherits: QObject.

This class was introduced in Qt Mobility 1.2.

Public Types

enum DiscoveryMode { MinimalDiscovery, FullDiscovery }
enum Error { NoError, DeviceDiscoveryError, UnknownError }

Public Functions

QBluetoothServiceDiscoveryAgent ( QObject * parent = 0 )
QBluetoothServiceDiscoveryAgent ( const QBluetoothAddress & remoteAddress, QObject * parent = 0 )
~QBluetoothServiceDiscoveryAgent ()
QList<QBluetoothServiceInfo> discoveredServices () const
Error error () const
QString errorString () const
bool isActive () const
void setUuidFilter ( const QList<QBluetoothUuid> & uuids )
void setUuidFilter ( const QBluetoothUuid & uuid )
QList<QBluetoothUuid> uuidFilter () const
  • 29 public functions inherited from QObject

Public Slots

void clear ()
void start ( DiscoveryMode mode = MinimalDiscovery )
void stop ()
  • 1 public slot inherited from QObject


void canceled ()
void error ( QBluetoothServiceDiscoveryAgent::Error error )
void finished ()
void serviceDiscovered ( const QBluetoothServiceInfo & info )

Additional Inherited Members

  • 1 property inherited from QObject
  • 1 public variable inherited from QObject
  • 4 static public members inherited from QObject
  • 7 protected functions inherited from QObject
  • 2 protected variables inherited from QObject

Detailed Description

The QBluetoothServiceDiscoveryAgent class provides an API for querying the services provided by a Bluetooth device.

To query the services provided by all contactable Bluetooth devices create an instance of QBluetoothServiceDiscoveryAgent, connect to either the serviceDiscovered() or finished() signals and call start().

     QBluetoothServiceDiscoveryAgent *discoveryAgent = new QBluetoothServiceDiscoveryAgent(this);

     connect(discoveryAgent, SIGNAL(serviceDiscovered(const QBluetoothServiceInfo&)),
             this, SLOT(serviceDiscovered(const QBluetoothServiceInfo&)));

     // Automatically delete agent when service discovery finishes.
     connect(discoveryAgent, SIGNAL(finished()), this, SLOT(deleteLater()));


By default a minimal service discovery is performed. In this mode the QBluetotohServiceInfo objects returned are guaranteed to contain only device and service UUID information. Depending on platform and device capabilities other service information may also be available. For most use cases this is adequate as QBluetoothSocket::connectToService() will perform additional discovery if required. If full service information is required pass FullDiscovery as the discoveryMode parameter to start().

Member Type Documentation

enum QBluetoothServiceDiscoveryAgent::DiscoveryMode

This enum describes the service discovery mode.

QBluetoothServiceDiscoveryAgent::MinimalDiscovery0Performs a minimal service discovery. The QBluetoothServiceInfo objects returned may be incomplete and are only guaranteed to contain device and service UUID information.
QBluetoothServiceDiscoveryAgent::FullDiscovery1Performs a full service discovery.

enum QBluetoothServiceDiscoveryAgent::Error

This enum describes errors that can occur during service discovery.

QBluetoothServiceDiscoveryAgent::NoError0No error.
QBluetoothServiceDiscoveryAgent::DeviceDiscoveryError1Error occurred during device discovery.
QBluetoothServiceDiscoveryAgent::UnknownError100An unidentified error occurred.

Member Function Documentation

QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent ( QObject * parent = 0 )

Constructs a new QBluetoothServiceDiscoveryAgent with parent. Services will be discovered on all contactable devices.

QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent ( const QBluetoothAddress & remoteAddress, QObject * parent = 0 )

Constructs a new QBluetoothServiceDiscoveryAgent for remoteAddress and with parent.

If remoteAddress is null services will be discovred on all contactable Bluetooth devices.

QBluetoothServiceDiscoveryAgent::~QBluetoothServiceDiscoveryAgent ()

Destructor for QBluetoothServiceDiscoveryAgent

void QBluetoothServiceDiscoveryAgent::canceled () [signal]

Signals the cancellation of the service discovery.

void QBluetoothServiceDiscoveryAgent::clear () [slot]

Clears the results of a previous service discovery.

QList<QBluetoothServiceInfo> QBluetoothServiceDiscoveryAgent::discoveredServices () const

Returns the list of all discovered services.

Error QBluetoothServiceDiscoveryAgent::error () const

Returns the type of error that last occurred. If service discovery is done on a signle address it will returns errors when trying to discover services on that device. If the alternate constructor is used and devices are discovered by a scan, then errors doing service discovery on individual devices are not saved and no signals are emitted. In this case errors are fairly normal since some devices may not respond to discovery or may no longer be in range. As such errors are surpressed. If no services are returned, it can be assumed no services could be discovered.

void QBluetoothServiceDiscoveryAgent::error ( QBluetoothServiceDiscoveryAgent::Error error ) [signal]

This signal is emitted when an error occurs. The error parameter describes the error that occurred.

QString QBluetoothServiceDiscoveryAgent::errorString () const

Returns a human-readable description of the last error that occurred when doing service discovery on a single device.

void QBluetoothServiceDiscoveryAgent::finished () [signal]

This signal is emitted when Bluetooth service discovery completes.

bool QBluetoothServiceDiscoveryAgent::isActive () const

Returns true if service discovery is currently active, otherwise returns false.

void QBluetoothServiceDiscoveryAgent::serviceDiscovered ( const QBluetoothServiceInfo & info ) [signal]

This signal is emitted when the Bluetooth service described by info is discovered.

void QBluetoothServiceDiscoveryAgent::setUuidFilter ( const QList<QBluetoothUuid> & uuids )

Sets the UUID filter to uuids. Only services matching the UUIDs in uuids will be returned.

An empty UUID list is equivalent to a list containing only QBluetoothUuid::PublicBrowseGroup.

See also uuidFilter().

void QBluetoothServiceDiscoveryAgent::setUuidFilter ( const QBluetoothUuid & uuid )

This is an overloaded member function, provided for convenience.

Sets the UUID filter to a list containing the single element uuid.

See also uuidFilter().

void QBluetoothServiceDiscoveryAgent::start ( DiscoveryMode mode = MinimalDiscovery ) [slot]

Starts service discovery. mode specifies the type of service discovery to perform.

See also DiscoveryMode.

void QBluetoothServiceDiscoveryAgent::stop () [slot]

Stops service discovery.

QList<QBluetoothUuid> QBluetoothServiceDiscoveryAgent::uuidFilter () const

Returns the UUID filter.

See also setUuidFilter().


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