QBluetoothDeviceDiscoveryAgent Class

  void MyClass::startDeviceDiscovery()
  {

      // Create a discovery agent and connect to its signals
      QBluetoothDeviceDiscoveryAgent *discoveryAgent = new QBluetoothDeviceDiscoveryAgent(this);
      connect(discoveryAgent, SIGNAL(deviceDiscovered(QBluetoothDeviceInfo)),
              this, SLOT(deviceDiscovered(QBluetoothDeviceInfo)));

      // Start a discovery
      discoveryAgent->start();

      //...
  }

  // In your local slot, read information about the found devices
  void MyClass::deviceDiscovered(const QBluetoothDeviceInfo &device)
  {
      qDebug() << "Found new device:" << device.name() << '(' << device.address().toString() << ')';
  }

Member Function Documentation

QBluetoothDeviceDiscoveryAgent::QBluetoothDeviceDiscoveryAgent(QObject *parent = Q_NULLPTR)

Constructs a new Bluetooth device discovery agent with parent parent.

QBluetoothDeviceDiscoveryAgent::QBluetoothDeviceDiscoveryAgent(const QBluetoothAddress &deviceAdapter, QObject *parent = Q_NULLPTR)

Constructs a new Bluetooth device discovery agent with parent.

It uses deviceAdapter for the device search. If deviceAdapter is default constructed the resulting QBluetoothDeviceDiscoveryAgent object will use the local default Bluetooth adapter.

If a deviceAdapter is specified that is not a local adapter error() will be set to InvalidBluetoothAdapterError. Therefore it is recommended to test the error flag immediately after using this constructor.

See also error().

QBluetoothDeviceDiscoveryAgent::~QBluetoothDeviceDiscoveryAgent()

Destructor for ~QBluetoothDeviceDiscoveryAgent()

[signal] void QBluetoothDeviceDiscoveryAgent::canceled()

This signal is emitted when device discovery is aborted by a call to stop().

[signal] void QBluetoothDeviceDiscoveryAgent::deviceDiscovered(const QBluetoothDeviceInfo &info)

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

The signal is emitted as soon as the most important device information has been collected. However, as long as the finished() signal has not been emitted the information collection continues even for already discovered devices. This is particularly true for signal strength information (RSSI). If signal strength information is required it is advisable to retrieve the device information via discoveredDevices() once the discovery has finished. This will yield the most recent RSSI information.

See also QBluetoothDeviceInfo::rssi().

QList<QBluetoothDeviceInfo> QBluetoothDeviceDiscoveryAgent::discoveredDevices() const

Returns a list of all discovered Bluetooth devices.

Error QBluetoothDeviceDiscoveryAgent::error() const

Returns the last error.

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

This signal is emitted when an error occurs during Bluetooth device discovery. The error parameter describes the error that occurred.

Note: Signal error is overloaded in this class. To connect to this one using the function pointer syntax, you must specify the signal type in a static cast, as shown in this example:

  connect(bluetoothDeviceDiscoveryAgent, static_cast<void(QBluetoothDeviceDiscoveryAgent::*)(QBluetoothDeviceDiscoveryAgent::Error)>(&QBluetoothDeviceDiscoveryAgent::error),
      [=](QBluetoothDeviceDiscoveryAgent::Error error){ /* ... */ });

See also error() and errorString().

QString QBluetoothDeviceDiscoveryAgent::errorString() const

Returns a human-readable description of the last error.

[signal] void QBluetoothDeviceDiscoveryAgent::finished()

This signal is emitted when Bluetooth device discovery completes. The signal is not going to be emitted if the device discovery finishes with an error.

bool QBluetoothDeviceDiscoveryAgent::isActive() const

Returns true if the agent is currently discovering Bluetooth devices, otherwise returns false.

[slot] void QBluetoothDeviceDiscoveryAgent::start()

Starts Bluetooth device discovery, if it is not already started.

The deviceDiscovered() signal is emitted as each device is discovered. The finished() signal is emitted once device discovery is complete.

[slot] void QBluetoothDeviceDiscoveryAgent::stop()

Stops Bluetooth device discovery. The cancel() signal is emitted once the device discovery is canceled. start() maybe called before the cancel signal is received. Once start() has been called the cancel signal from the prior discovery will be discarded.