【发布时间】：2017-11-04 13:06:09
【问题描述】：
我将 Mac 设置为蓝牙配件，使用 CoreBluetooth 作为CBPeripheralManager。 Mac 正在针对一组特征 CBUUID 做广告，一旦它有订阅者，我单击一个按钮以每半秒流式传输一个 UTF-8 编码的时间戳。
我将 iPhone 设置为CBCentralManager，订阅了相应的特性。每次收到数据并且应用程序处于活动状态时，我都会使用解码的时间戳更新 iPhone 的 UI。 bluetooth-central 后台模式在.plist 文件中设置。
iPhone 继续调试打印并更新 UI 的时间戳约 25 秒，然后停止。无论应用程序是在前台还是后台，都会发生这种情况。 编辑：此时CBPeripheralManager 收到didUnsubscribeFrom characteristic 回调。我看不出有任何理由会调用 didUnsubscribeFrom，不知道为什么总是在 25 秒后。
CBPeripheralManager 继续愉快地发送它的时间戳。 CBPeripheralManager 的 updateData(_:for:onSubscribedCentrals:) 调用的返回值始终为 true，表示队列永远不会满。
这里涉及到很多代码，展示了最相关的。
来自CBCentralManager 应用程序：
func centralManagerDidUpdateState(_ central: CBCentralManager) {
print(central.state.rawValue)
centralManager.scanForPeripherals(withServices: [timeUUID], options: nil)
print("scanning")
}
func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
peripheral.delegate = self
peripheral.discoverServices(nil)
print("connected")
}
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
print(peripheral.name as Any)
print(advertisementData[CBAdvertisementDataServiceUUIDsKey] as! Array<CBUUID>)
self.peripheralController = peripheral
self.centralManager.connect(peripheral, options: nil)
}
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
if service.uuid.uuidString == timeUUID.uuidString {
peripheralController.setNotifyValue(true, for: service.characteristics!.first!)
peripheralController.readValue(for: service.characteristics!.first!) // EDIT: This was the offending line
}
}
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if characteristic.uuid.uuidString == timeUUID.uuidString {
if let valueFrom = characteristic.value {
if let this = String(data: valueFrom, encoding: .utf8) {
if UIApplication.shared.applicationState == .active {
label.text = this
print("ACTIVE \(this)")
} else if UIApplication.shared.applicationState == .background {
print("BACKGROUND \(this)")
} else if UIApplication.shared.applicationState == .inactive {
print("INACTIVE \(this)")
}
}
}
}
}
来自CBPeripheralManager 应用程序：
func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
myCharacteristic = CBMutableCharacteristic(type: myServiceUUID, properties: [CBCharacteristicProperties.read, CBCharacteristicProperties.notify], value: nil, permissions: CBAttributePermissions.readable)
let myService = CBMutableService(type: myServiceUUID, primary: true)
myService.characteristics = [myCharacteristic]
bluetoothController.add(myService)
}
func peripheralManager(_ peripheral: CBPeripheralManager, central: CBCentral, didSubscribeTo characteristic: CBCharacteristic) {
print(characteristic.uuid)
subscriber = central
}
func peripheralManager(_ peripheral: CBPeripheralManager, central: CBCentral, didUnsubscribeFrom characteristic: CBCharacteristic) {
print(characteristic)
print("unsubscribe")
}
func repeatAdvertisement() {
timer = Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { [unowned self] (timerRef) in
guard let maybeTimer = self.timer, maybeTimer.isValid else { return }
let datum = Date()
let stringFromDate = self.dateFormatter.string(from: datum)
let data = stringFromDate.data(using: .utf8)
print(data!.count)
// myCharacteristic.value = data
let myService = CBMutableService(type: self.myServiceUUID, primary: true)
myService.characteristics = [self.myCharacteristic]
let did = self.bluetoothController.updateValue(data!, for: self.myCharacteristic as! CBMutableCharacteristic, onSubscribedCentrals: [self.subscriber])
print("timed \(stringFromDate) \(did)")
}
}
func advertise() {
if timer == nil {
repeatAdvertisement()
} else {
timer?.invalidate()
timer = nil
}
}
如果您需要任何其他信息，请告诉我。
【问题讨论】：
标签： ios swift bluetooth-lowenergy core-bluetooth cbcentralmanager