如何以编程方式获取 iPhone 中蓝牙的状态（开/关）

Question

我试图以编程方式获取 iPhone/iPod 蓝牙的状态，无论它是打开还是关闭。 是否可以使用某些 Apple API 或第三方 API。

Answer 1

对 Sam 的回答进行了一些研究，我想我会分享
您可以在不使用私有 API 的情况下执行此操作，但有一些注意事项：

• 它仅适用于 iOS 5.0+
• 它仅适用于以下设备：
  支持蓝牙 LE 规范（iPhone 4S+、第 5 代 iPod+、iPad
  第三代+)
• 简单地分配该类将导致您的应用程序向用户请求使用蓝牙堆栈的权限（可能不需要），如果他们拒绝，您将看到的唯一内容是 CBCentralManagerStateUnauthorized iOS7+ 修订版：现在可以防止上述删除线，请参阅下面的评论，其中指向 此答案，其中解释了您可以设置 CoreBluetooth将 CBCentralManagerOptionShowPowerAlertKey 选项设置为 NO 以防止权限提示。
• 蓝牙状态的检索是异步且连续的。您将需要设置一个委托来获取状态更改，因为检查新分配的蓝牙管理器的状态将返回 CBCentralManagerStateUnknown

话虽如此，此方法似乎确实提供了蓝牙堆栈状态的实时更新。

包含 CoreBluetooth 框架后，

#import <CoreBluetooth/CoreBluetooth.h>

这些测试很容易使用以下方法执行：

- (void)detectBluetooth
{
    if(!self.bluetoothManager)
    {
        // Put on main queue so we can call UIAlertView from delegate callbacks.
        self.bluetoothManager = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()];
    }
    [self centralManagerDidUpdateState:self.bluetoothManager]; // Show initial state
}

- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
    NSString *stateString = nil;
    switch(self.bluetoothManager.state)
    {
        case CBCentralManagerStateResetting: stateString = @"The connection with the system service was momentarily lost, update imminent."; break;
        case CBCentralManagerStateUnsupported: stateString = @"The platform doesn't support Bluetooth Low Energy."; break;
        case CBCentralManagerStateUnauthorized: stateString = @"The app is not authorized to use Bluetooth Low Energy."; break;
        case CBCentralManagerStatePoweredOff: stateString = @"Bluetooth is currently powered off."; break;
        case CBCentralManagerStatePoweredOn: stateString = @"Bluetooth is currently powered on and available to use."; break;
        default: stateString = @"State unknown, update imminent."; break;
    }
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Bluetooth state"
                                                     message:stateString
                                                    delegate:nil
                                          cancelButtonTitle:@"ok" otherButtonTitles: nil];
    [alert show];
}

Answer 2

要禁用默认警报消息，您只需要在实例化 CBPeripheralManager 时传递选项字典：

在 iOS8+ 上测试的 SWIFT

import CoreBluetooth

//Define class variable in your VC/AppDelegate
var bluetoothPeripheralManager: CBPeripheralManager?

 //On viewDidLoad/didFinishLaunchingWithOptions
let options = [CBCentralManagerOptionShowPowerAlertKey:0] //<-this is the magic bit!
bluetoothPeripheralManager = CBPeripheralManager(delegate: self, queue: nil, options: options)

显然，您还需要实现 CKManagerDelegate 委托方法 PeripheralManagerDidUpdateState，如上所述：

func peripheralManagerDidUpdateState(peripheral: CBPeripheralManager!) {

    var statusMessage = ""

    switch peripheral.state {
    case .poweredOn:
        statusMessage = "Bluetooth Status: Turned On"

    case .poweredOff:
        statusMessage = "Bluetooth Status: Turned Off"

    case .resetting:
        statusMessage = "Bluetooth Status: Resetting"

    case .unauthorized:
        statusMessage = "Bluetooth Status: Not Authorized"

    case .unsupported:
        statusMessage = "Bluetooth Status: Not Supported"

    case .unknown:
        statusMessage = "Bluetooth Status: Unknown"
    }

    print(statusMessage)

    if peripheral.state == .poweredOff {
        //TODO: Update this property in an App Manager class
    }
}

Answer 3

这个答案已经从原来的 Objective-C 更新到了 Swift 4.0。

假设您已经创建了蓝牙管理器并将委托分配给 ViewController 类。

import CoreBluetooth

extension ViewController : CBCentralManagerDelegate {
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        switch central.state {
        case .poweredOn:
            print("powered on")
        case .poweredOff:
            print("powered off")
        case .resetting:
            print("resetting")
        case .unauthorized:
            print("unauthorized")
        case .unsupported:
            print("unsupported")
        case .unknown:
            print("unknown")
        }
    }
}

Answer 4

BadPirate 答案的一些更新，在 iOS7 中，您可以设置中央管理器在分配管理器对象时不显示警报，方法是将键“CBCentralManagerOptionShowPowerAlertKey”设置为 0 的 NSDictionary。

self.cbManager = [[CBCentralManager alloc] initWithDelegate:self
                                                          queue:nil
                                                        options:
                      [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:0]
                                                  forKey:CBCentralManagerOptionShowPowerAlertKey]];

Answer 5

在 iOS 5 及更高版本上有一种使用 CoreBluetooth 的方法。您可以使用的类是 CBCentralManager。它有一个属性“状态”，您可以检查蓝牙是否打开。 （枚举 CBCentralManagerState 具有您要检查的值）。

Answer 6

一旦您完成了 CBCentralManager 设置，您就可以从 委托方法或直接委托方法。

import CoreBluetooth

class Manager {
    let centralManager = CBCentralManager(delegate: self, queue: nil)

    var isBTTurnedOn: Bool {
        return centralManager.state == .poweredOn
    }

    var isAuthorized: Bool {
        if #available(iOS 13.0, *) {
            return centralManager.authorization == .allowedAlways
        } else {
            return true
        }
    }
}

Answer 7

这个解决方案有点老了，在苹果推出核心蓝牙之前

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
        // Override point for customization after application launch.


        Class BluetoothManager = objc_getClass( "BluetoothManager" ) ;
        id btCont = [BluetoothManager sharedInstance] ;
        [self performSelector:@selector(status:) withObject:btCont afterDelay:1.0f] ;

        return YES ;
    }


    - (void)status:(id)btCont
    {
        BOOL currentState = [btCont enabled] ;
        //check the value of currentState 

    }