在CBCentralManager委托方法didDiscoverPeripheral：从来没有调用

我在主队列中的viewdidload初始化CBCenteralManager 。 第一次更新状态方法被调用，开始扫描蓝牙设备，但didDiscoverPeripheral:委托方法永远不会被调用。

代码是：

 - (void)viewDidLoad { [super viewDidLoad]; self.CM = [[CBCentralManager alloc]initWithDelegate:self queue:nil]; } -(void)centralManagerDidUpdateState:(CBCentralManager *)central{ if (central.state == CBCentralManagerStatePoweredOn) { [self.CM scanForPeripheralsWithServices:nil options:nil]; } } - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral(CBPeripheral*)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI { } -(void)centralManager:(CBCentralManager *)central didRetrievePeripherals:(NSArray *)peripherals{ } -(void)centralManager:(CBCentralManager *)central didRetrieveConnectedPeripherals:(NSArray *)peripherals{ } -(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{ } -(void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{ } -(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral{ }