How to get the status of bluetooth (ON/OFF) in iphone programmatically

Question

I trying to get the Status of iPhone/iPod Bluetooth that whether it is ON or OFF programmatically. Is it possible using some Apple API or third party API.

Solution 1

A little bit of research into Sam's answer that I thought I'd share You can do so without utilizing private API, but with a few caveats:

• It will only work on iOS 5.0+
• It will only work on devices that support the bluetooth LE spec (iPhone 4S+, 5th Generation iPod+, iPad 3rd Generation+)
• Simply allocating the class will cause your application to ask permission to use the bluetooth stack from the user (may not be desired), and if they refuse, the only thing you'll see is CBCentralManagerStateUnauthorized iOS7+ Revision: Aforementioned strike-through can now be prevented, see comments below which point to this answer which explains you can set CoreBluetooth's CBCentralManagerOptionShowPowerAlertKey option to NO to prevent permissions prompt.
• Retrieval of bluetooth state is async, and continuous. You will need to setup a delegate to get state changes, as checking the state of a freshly allocated bluetooth manager will return CBCentralManagerStateUnknown

That being said, this method does seem to provide real time updates of bluetooth stack state.

After including the CoreBluetooth framework,

#import <CoreBluetooth/CoreBluetooth.h>

These tests were easy to perform using:

- (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];
}

Solution 2

To disable the default alert message you just need to pass through an option dictionary when you instantiate the CBPeripheralManager:

SWIFT tested on iOS8+

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)

Obviously you also need to implement the CKManagerDelegate delegate method peripheralManagerDidUpdateState as outlined above as well:

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
    }
}

Solution 3

This answer has been updated from the original Objective-C to Swift 4.0.

It is assumed that you have already created a bluetooth manager and assigned the delegate to the ViewController class.

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")
        }
    }
}

Solution 4

Some updates on BadPirate's answer, with iOS7 you can set the central manager not to show the alert when allocating the manager object by giving it a NSDictionary that has key "CBCentralManagerOptionShowPowerAlertKey" set to 0.

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

Solution 5

There is a way on iOS 5 and above using CoreBluetooth. The class you can use is CBCentralManager. It has a property 'state' that you can check to see if Bluetooth is on or not. (the enum CBCentralManagerState has the value(s) you want to check against).

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Comments

[domsom]

This will only work for devices with BT LE, i.e. iPhone 4S+, iPad 3+

[Yevhen Dubinin]

You mentioned that implicitly, but for consistency: declare property @property (nonatomic, strong) CBCentralManager* bluetoothManager; and set your class conforms to protocol CBCentralManagerDelegate

[esreli]

This hasn't worked for me. Has someone gotten this to work for them? iOS7+

[bompf]

You can avoid the alert message using the designated initializer on CBCentralManager, check out this answer: stackoverflow.com/a/19367494/823483

[LS_]

is this method accepted by apple? Or they will reject the app using it?

[BadPirate]

@Signo - No issues with Apple, though some reports that it's not working anymore.

[Legolas]

how to add property CBPeripheralManager in swift.It says cannot find an initializer for type "CBPeripheralManager"

[Awesomeness]

@Aravind.A add import CoreBluetooth to the top of your source file

[Maksim]

This piece of code is great for silent check for bluetooth status (on/off, etc.)

[NickG]

Does this work in the background, or only when the app is on-screen?

[Albert Renshaw]

@BadPirate It indeed still works now. People are likely reading the state immediately (which will always return (int)0), rather than waiting for the delegate callback.