如何检测用户的iPhone关闭或开启的蓝牙？

Question

我试图检测用户的iPhone开启或关闭的蓝牙。如果它是关我想发送通知给用户打开它。到目前为止，我已经这样做了：

import CoreBluetooth

  class ViewController: UIViewController, CLLocationManagerDelegate,AVCaptureMetadataOutputObjectsDelegate,CBManager {   

 var myBTManager = CBPeripheralManager(delegate: self, queue: nil, options: nil)

  }

func peripheralManagerDidUpdateState(peripheral: CBPeripheralManager!) {
    print(#function)
    if peripheral.state == CBManagerState.poweredOn {
        print("Broadcasting...")

    //    myBTManager!.startAdvertising(_broadcastBeaconDict)
    } else if peripheral.state == CBManagerState.poweredOff {
        print("Stopped")
        myBTManager!.stopAdvertising()
    } else if peripheral.state == CBManagerState.unsupported {
        print("Unsupported")
    } else if peripheral.state == CBManagerState.unauthorized {
        print("This option is not allowed by your application")
    }
}

但正如你从图中可以看到的那样，出了点问题.

你能帮我解决一下这个问题，我是swift和CoreBluetooth技术的新手。我也使用Reachability来检测Wi-Fi连接，所以如果它也适用于蓝牙，我宁愿使用Reachability。

Answer 1

1. 你应该实现协议CBPeripheralManagerDelegate，所以用CBManager替换你的class定义行中的CBPeripheralManagerDelegate。
2. 在Swift 3中，peripheralManagerDidUpdateState的签名现在是： func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager)
3. 您无法在课程创建时初始化CBPeripheralManager，因为self仅在课程初始化后才可用。相反，让你的财产： var myBTManager: CBPeripheralManager? 并在viewDidLoad中初始化它：

   override func viewDidLoad() {
       ...       
       myBTManager = CBPeripheralManager(delegate: self, queue: nil, options: nil)
       ...
   }

Answer 2

您可以使用CBCentralMangerDelegate方法：

    public func centralManager(_ central: CBCentralManager, willRestoreState dict: [String : Any]) {
            if central.state == .poweredOn {
                //Bluetooth is on
           } else if central.state == .poweredOff {
                //Bluetooth is off
           }
    }