Qt Bluetooth - no devices discovered.

jenya7

@jsulm said in Qt Bluetooth - no devices discovered.:

@jenya7 said in Qt Bluetooth - no devices discovered.:

Is it OK?

Why did you comment out the connect?

for debug. I still get the error.
On Windows I get a different error - error: multiple definition of `Device::scanFinished()' in moc_device.cpp.
first defined here device.cpp.
I wonder how can it be - moc file is a generated file after build.

jsulm

@jenya7 said in Qt Bluetooth - no devices discovered.:

I wonder how can it be - moc file is a generated file after build

It is probably a remnant from previos version when scanFinished was declared as signal.
Do a complete rebuild: delete build folder, run qmake and build.

jenya7

@jsulm said in Qt Bluetooth - no devices discovered.:

@jenya7 said in Qt Bluetooth - no devices discovered.:

I wonder how can it be - moc file is a generated file after build

It is probably a remnant from previos version when scanFinished was declared as signal.
Do a complete rebuild: delete build folder, run qmake and build.

Deleted all from the build folder. Clean. Rebuild. I see new files created. The same problem.
Renamed scanFinished for scanCompleted. Still the same problem.

jsulm

This post is deleted!

jsulm

@jenya7 said in Qt Bluetooth - no devices discovered.:

On Windows I get a different error - error: multiple definition of `Device::scanFinished()' in moc_device.cpp.

Just realised: this is in Device class.
Please show Device code (header and cpp).
You probably defined scanFinished() in cpp file, you should not do that for signals!

jenya7

@jsulm
I see. Now on Windows it compiles OK. On Linux the same 'vtable' problem.

jsulm

@jenya7 said in Qt Bluetooth - no devices discovered.:

On Linux the same 'vtable' problem

Exact same code?
Do a full rebuild.

jenya7

@jsulm
yes.
I've noticed in device.h at the beginning

class Device: public QObject
{
    Q_OBJECT
    Q_PROPERTY(QVariant devicesList READ getDevices NOTIFY devicesUpdated)
    Q_PROPERTY(QVariant servicesList READ getServices NOTIFY servicesUpdated)
    Q_PROPERTY(QVariant characteristicList READ getCharacteristics NOTIFY characteristicsUpdated)
    Q_PROPERTY(QString update READ getUpdate WRITE setUpdate NOTIFY updateChanged)
    Q_PROPERTY(bool useRandomAddress READ isRandomAddress WRITE setRandomAddress NOTIFY randomAddressChanged)
    Q_PROPERTY(bool state READ state NOTIFY stateChanged)
    Q_PROPERTY(bool controllerError READ hasControllerError)

//and so on

those Q_PROPERTY - do I need it? it's a QML related stuff.
I took the class from a QML project.

jsulm

@jenya7 said in Qt Bluetooth - no devices discovered.:

those Q_PROPERTY - do I need it?

If you don't use them then you don't need them.

jenya7

@jsulm
oops. I did "Run qmake" then "Build" - and it's compiles, no errors.

now if I uncomment
connect(&bt_device, &Device::scanFinished, this, &BT_DEVICE::ScanFinished);
I get a run time exception

The inferior stopped because it received a signal from the operating system.

in devise.h

signals:
    void scanFinished();

in my h

public slots:
    void ScanFinished();

seems OK.

So this is wrong

Device::Device()
{
    connect(discoveryAgent, &QBluetoothDeviceDiscoveryAgent::finished, this, &Device::scanFinished);
}

I connect a signal to a signal.

Jamie Biswas

This post is deleted!

jsulm

@jenya7 said in Qt Bluetooth - no devices discovered.:

I get a run time exception

Then run through debugger to see where and why exactly it is crashing...
I guess it is crashing inside ScanFinished() slot.

Connecting a signal to another signal is perfectly valid.