android - How to choose local adapter when connecting to service with QBluetoothSocket

Question

In the presence of multiple Bluetooth adapters, is it possible to specify which local adapter to use when creating a QBluetoothSocket or calling QBluetoothSocket::connectToService()? I'm interested in Linux/BlueZ as well as Android (where it is not even clear whether multiple Bluetooth adapters are supported by the Bluetooth stack).

Answer 1

QBluetoothLocalDevice(QBluetoothAddress)从 Qt 5.6.2 开始，除了、和 之外QBluetoothDeviceDiscoveryAgent(QBluetoothAddress)，还没有这样的功能。这些仅在 Linux 上有意义，在 Android 上无效，因为 Android 蓝牙堆栈似乎不支持多个加密狗，至少目前如此。QBluetoothServiceDiscoveryAgent(QBluetoothAddress)QBluetoothServer::listen(QBluetoothAddress)

但是，在带有 BlueZ 的 Linux 上，可以使用 BlueZ c API 选择本地适配器：

#include <sys/socket.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/rfcomm.h>

...

QBluetoothSocket* socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol);

struct sockaddr_rc loc_addr;
loc_addr.rc_family = AF_BLUETOOTH;

int socketDescriptor = ::socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM);
if(socketDescriptor < 0){
    qCritical() << strerror(errno);
    return;
}

const char* localMacAddr = "XX:XX:XX:XX:XX:XX"; //MAC address of the local adapter
str2ba(localMacAddr, &(loc_addr.rc_bdaddr));

if(bind(socketDescriptor, (struct sockaddr*)&loc_addr, sizeof(loc_addr)) < 0){
    qCritical() << strerror(errno);
    return;
}

if(!socket->setSocketDescriptor(socketDescriptor, QBluetoothServiceInfo::RfcommProtocol, QBluetoothSocket::UnconnectedState)){
    qCritical() << "Couldn't set socketDescriptor";
    return;
}

socket->connectToService(...);

该项目.pro必须包含以下内容：

CONFIG += link_pkgconfig
PKGCONFIG += bluez

可能将其集成到 Qt API 中的相应功能请求：https ://bugreports.qt.io/browse/QTBUG-57382