iOS蓝牙retrievePeripherals导致EXC_BAD_ACCESS崩溃

Question

I need to periodically reconnect to a peripheral, but trying to re-connect crashes.

First, my central scans for peripherals' UUID, then it connects, then it stores the peripheral.UUID into a CFUUIDRef variable, and then disconnects. Next, to re-connect it retrieves the UUID from variable, then either crashes with "EXC_BAD_ACCESS" when it does retreivePeripherals, or a little later when it does the subsequent didRetrievePeripherals.

Maybe I'm not storing the UUID correctly, but I don't see the bug. Thanks.

Here's the code ..........

-(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
    ///////////////////////   C E N T R A L   C O N N E C T E D   P E R I P H E R A L   //////////////////////

    [self.centralManager   stopScan];
    // Make sure we get the discovery callbacks
    peripheral.delegate = pwr_tx_management;

    switch( PWR_TX_manager.present_operation )
    {
        case POLLING_FOR_GENERIC_DVINEWAVE_DEVICE:
            if( dbg_ev )        printf("1");        
            // Add new record for connection device to local system status database:
            update_device_record( &packed_ad_record    );       //      ==>  device_record_index
            // Store peripheral UUID for later, perioed re-connection for polling:
            area_device_status[ device_area ][ device_record_index ].peripheral_UUID = peripheral.UUID;
                                 // uses declaration:  CFUUIDRef            peripheral_UUID;

    // Disconnect:        !!!
        [self.centralManager   cancelPeripheralConnection:   peripheral];
        break;


        case OPERATION_SPECIFIC_POLLING:
                                        NSLog( @"(7) didConnectPeripheral   " );
            if( dbg_ev )        printf("2");        
            // Proceed with reading device's status and updating local database:
                [peripheral   discoverServices:nil];    // request service, characteristics, then request device send its packed status record

            break;
        default:
            break;
    }    
}





// Connects to device specificed by index next_dbase_record .
void connect_specific_device( void )
{
                                                        NSLog( @"(5) connect_specific_device    - next_dbase_record = %d", next_dbase_record );
    CFUUIDRef uuid = area_device_status[ device_area ][ next_dbase_record ].peripheral_UUID;

    if( uuid )
    {
        // Request call to didRetrievePeripherals() with CBPeripheral:
        [pwr_tx_management.centralManager retrievePeripherals:[NSArray arrayWithObject: (id)CFBridgingRelease(uuid)]];     <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< crashes here with:  Thread 1: EXC_BAD_ACCESS
    }
    else
    {
        NSLog( @"   - missing area_device_status[][].peripheral_UUID ");
    }

}



// Iniates connection to peripheral device specified before by retrievePeripherals.
- (void) centralManager:(CBCentralManager *)central didRetrievePeripherals:(CBPeripheral *)peripheral
{
    NSLog( @"(6) didRetrievePeripherals");
    [central   connectPeripheral:peripheral   options:nil];
}

Answer 1

Let me preface this by saying I'm writing this from my cell phone in a car, so excuse me for the poor formatting. Ill just point out the main problem I see. You're not adopting the right delegate method:

It is:

- (void) centralManager:(CBCentralManager *)central didRetrievePeripherals:(NSArray *) peripherals

Not this:

- (void) centralManager:(CBCentralManager *)central didRetrievePeripherals:(CBPeripheral *)peripheral

Also I don't see why you're doing that cfbridgingrelease . Just pass it in as @[(id)yourCfuuidref] . You didn't create that cfuuid.

Answer 2

The solution was to store the ASCII UUID, and use use retrieveConnectedPeripherals as well as retreivePeripherals. Storing the pointer probably failed because the data was not retained. I also implemented tdevoy's solution. didRetrievePeripherals gets called but its peripherals list is empty, so I added to it retrieveConnectedPeripherals and didRetrieveConnectedPeripherals, which gets called, and lists the peripheral, which I successfully connect to. (Apple Prog. guide for these is vague and lacks example code.)