版本记录

前言

很多时候我们需要使用蓝牙，在使用的时候我们都需要判断蓝牙当前的使用状态，然后再做相关的逻辑处理，下面我就简单的实现了下，希望对大家有所帮助。

功能目标

获取蓝牙当前的应用状态。

功能实现

1.几个重要的类和框架

• <CoreBluetooth/CoreBluetooth.h>框架
• CBCentralManager
• CBManager

<CoreBluetooth/CoreBluetooth.h>

这里就是和蓝牙相关的框架，所有的实现都在这里完成。

#ifndef _CORE_BLUETOOTH_H_
#define _CORE_BLUETOOTH_H_
#endif

#import <CoreBluetooth/CBCentralManager.h>
#import <CoreBluetooth/CBPeripheralManager.h>

#import <CoreBluetooth/CBPeripheral.h>
#import <CoreBluetooth/CBCentral.h>

#import <CoreBluetooth/CBService.h>
#import <CoreBluetooth/CBCharacteristic.h>
#import <CoreBluetooth/CBDescriptor.h>

#import <CoreBluetooth/CBError.h>
#import <CoreBluetooth/CBUUID.h>
#import <CoreBluetooth/CBAdvertisementData.h>
#import <CoreBluetooth/CBATTRequest.h>

CBCentralManager

给出部分API。

#ifndef _CORE_BLUETOOTH_H_
#warning Please do not import this header file directly. Use <CoreBluetooth/CoreBluetooth.h> instead.
#endif

#import <CoreBluetooth/CBAdvertisementData.h>
#import <CoreBluetooth/CBCentralManagerConstants.h>
#import <CoreBluetooth/CBDefines.h>
#import <CoreBluetooth/CBManager.h>
#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

/*!
 *  @enum CBCentralManagerState
 *
 *  @discussion Represents the current state of a CBCentralManager.
 *
 *  @constant CBCentralManagerStateUnknown       State unknown, update imminent.
 *  @constant CBCentralManagerStateResetting     The connection with the system service was momentarily lost, update imminent.
 *  @constant CBCentralManagerStateUnsupported   The platform doesn't support the Bluetooth Low Energy Central/Client role.
 *  @constant CBCentralManagerStateUnauthorized  The application is not authorized to use the Bluetooth Low Energy Central/Client role.
 *  @constant CBCentralManagerStatePoweredOff    Bluetooth is currently powered off.
 *  @constant CBCentralManagerStatePoweredOn     Bluetooth is currently powered on and available to use.
 *
 */
typedef NS_ENUM(NSInteger, CBCentralManagerState) {
    CBCentralManagerStateUnknown = CBManagerStateUnknown,
    CBCentralManagerStateResetting = CBManagerStateResetting,
    CBCentralManagerStateUnsupported = CBManagerStateUnsupported,
    CBCentralManagerStateUnauthorized = CBManagerStateUnauthorized,
    CBCentralManagerStatePoweredOff = CBManagerStatePoweredOff,
    CBCentralManagerStatePoweredOn = CBManagerStatePoweredOn,
} NS_DEPRECATED(NA, NA, 5_0, 10_0, "Use CBManagerState instead");

@protocol CBCentralManagerDelegate;
@class CBUUID, CBPeripheral;

/*!
 *  @class CBCentralManager
 *
 *  @discussion Entry point to the central role. Commands should only be issued when its state is <code>CBCentralManagerStatePoweredOn</code>.
 *
 */
NS_CLASS_AVAILABLE(10_7, 5_0)
CB_EXTERN_CLASS @interface CBCentralManager : CBManager

/*!
 *  @property delegate
 *
 *  @discussion The delegate object that will receive central events.
 *
 */
@property(nonatomic, weak, nullable) id<CBCentralManagerDelegate> delegate;

/*!
 *  @property isScanning
 *
 *  @discussion Whether or not the central is currently scanning.
 *
 */
@property(nonatomic, assign, readonly) BOOL isScanning NS_AVAILABLE(NA, 9_0);

- (instancetype)init;

/*!
 *  @method initWithDelegate:queue:
 *
 *  @param delegate The delegate that will receive central role events.
 *  @param queue    The dispatch queue on which the events will be dispatched.
 *
 *  @discussion     The initialization call. The events of the central role will be dispatched on the provided queue.
 *                  If <i>nil</i>, the main queue will be used.
 *
 */
- (instancetype)initWithDelegate:(nullable id<CBCentralManagerDelegate>)delegate
                           queue:(nullable dispatch_queue_t)queue;

/*!
 *  @method initWithDelegate:queue:options:
 *
 *  @param delegate The delegate that will receive central role events.
 *  @param queue    The dispatch queue on which the events will be dispatched.
 *  @param options  An optional dictionary specifying options for the manager.
 *
 *  @discussion     The initialization call. The events of the central role will be dispatched on the provided queue.
 *                  If <i>nil</i>, the main queue will be used.
 *
 *  @seealso        CBCentralManagerOptionShowPowerAlertKey
 *  @seealso        CBCentralManagerOptionRestoreIdentifierKey
 *
 */
- (instancetype)initWithDelegate:(nullable id<CBCentralManagerDelegate>)delegate
                           queue:(nullable dispatch_queue_t)queue
                         options:(nullable NSDictionary<NSString *, id> *)options NS_AVAILABLE(NA, 7_0) NS_DESIGNATED_INITIALIZER;

/*!
 *  @method retrievePeripheralsWithIdentifiers:
 *
 *  @param identifiers  A list of <code>NSUUID</code> objects.
 *
 *  @discussion         Attempts to retrieve the <code>CBPeripheral</code> object(s) with the corresponding <i>identifiers</i>.
 *
 *  @return             A list of <code>CBPeripheral</code> objects.
 *
 */
- (NSArray<CBPeripheral *> *)retrievePeripheralsWithIdentifiers:(NSArray<NSUUID *> *)identifiers NS_AVAILABLE(NA, 7_0);

/*!
 *  @method retrieveConnectedPeripheralsWithServices
 *
 *  @discussion Retrieves all peripherals that are connected to the system and implement any of the services listed in <i>serviceUUIDs</i>.
 *              Note that this set can include peripherals which were connected by other applications, which will need to be connected locally
 *              via {@link connectPeripheral:options:} before they can be used.
 *
 *  @return     A list of <code>CBPeripheral</code> objects.
 *
 */
- (NSArray<CBPeripheral *> *)retrieveConnectedPeripheralsWithServices:(NSArray<CBUUID *> *)serviceUUIDs NS_AVAILABLE(NA, 7_0);

/*!
 *  @method scanForPeripheralsWithServices:options:
 *
 *  @param serviceUUIDs A list of <code>CBUUID</code> objects representing the service(s) to scan for.
 *  @param options      An optional dictionary specifying options for the scan.
 *
 *  @discussion         Starts scanning for peripherals that are advertising any of the services listed in <i>serviceUUIDs</i>. Although strongly discouraged,
 *                      if <i>serviceUUIDs</i> is <i>nil</i> all discovered peripherals will be returned. If the central is already scanning with different
 *                      <i>serviceUUIDs</i> or <i>options</i>, the provided parameters will replace them.
 *                      Applications that have specified the <code>bluetooth-central</code> background mode are allowed to scan while backgrounded, with two
 *                      caveats: the scan must specify one or more service types in <i>serviceUUIDs</i>, and the <code>CBCentralManagerScanOptionAllowDuplicatesKey</code>
 *                      scan option will be ignored.
 *
 *  @see                centralManager:didDiscoverPeripheral:advertisementData:RSSI:
 *  @seealso            CBCentralManagerScanOptionAllowDuplicatesKey
 *  @seealso            CBCentralManagerScanOptionSolicitedServiceUUIDsKey
 *
 */
- (void)scanForPeripheralsWithServices:(nullable NSArray<CBUUID *> *)serviceUUIDs options:(nullable NSDictionary<NSString *, id> *)options;

/*!
 *  @method stopScan:
 *
 *  @discussion Stops scanning for peripherals.
 *
 */
- (void)stopScan;

/*!
 *  @method connectPeripheral:options:
 *
 *  @param peripheral   The <code>CBPeripheral</code> to be connected.
 *  @param options      An optional dictionary specifying connection behavior options.
 *
 *  @discussion         Initiates a connection to <i>peripheral</i>. Connection attempts never time out and, depending on the outcome, will result
 *                      in a call to either {@link centralManager:didConnectPeripheral:} or {@link centralManager:didFailToConnectPeripheral:error:}.
 *                      Pending attempts are cancelled automatically upon deallocation of <i>peripheral</i>, and explicitly via {@link cancelPeripheralConnection}.
 *
 *  @see                centralManager:didConnectPeripheral:
 *  @see                centralManager:didFailToConnectPeripheral:error:
 *  @seealso            CBConnectPeripheralOptionNotifyOnConnectionKey
 *  @seealso            CBConnectPeripheralOptionNotifyOnDisconnectionKey
 *  @seealso            CBConnectPeripheralOptionNotifyOnNotificationKey
 *
 */
- (void)connectPeripheral:(CBPeripheral *)peripheral options:(nullable NSDictionary<NSString *, id> *)options;

/*!
 *  @method cancelPeripheralConnection:
 *
 *  @param peripheral   A <code>CBPeripheral</code>.
 *
 *  @discussion         Cancels an active or pending connection to <i>peripheral</i>. Note that this is non-blocking, and any <code>CBPeripheral</code>
 *                      commands that are still pending to <i>peripheral</i> may or may not complete.
 *
 *  @see                centralManager:didDisconnectPeripheral:error:
 *
 */
- (void)cancelPeripheralConnection:(CBPeripheral *)peripheral;

@end


/*!
 *  @protocol CBCentralManagerDelegate
 *
 *  @discussion The delegate of a {@link CBCentralManager} object must adopt the <code>CBCentralManagerDelegate</code> protocol. The
 *              single required method indicates the availability of the central manager, while the optional methods allow for the discovery and
 *              connection of peripherals.
 *
 */
@protocol CBCentralManagerDelegate <NSObject>

@required

/*!
 *  @method centralManagerDidUpdateState:
 *
 *  @param central  The central manager whose state has changed.
 *
 *  @discussion     Invoked whenever the central manager's state has been updated. Commands should only be issued when the state is
 *                  <code>CBCentralManagerStatePoweredOn</code>. A state below <code>CBCentralManagerStatePoweredOn</code>
 *                  implies that scanning has stopped and any connected peripherals have been disconnected. If the state moves below
 *                  <code>CBCentralManagerStatePoweredOff</code>, all <code>CBPeripheral</code> objects obtained from this central
 *                  manager become invalid and must be retrieved or discovered again.
 *
 *  @see            state
 *
 */
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;

@optional

/*!
 *  @method centralManager:willRestoreState:
 *
 *  @param central      The central manager providing this information.
 *  @param dict         A dictionary containing information about <i>central</i> that was preserved by the system at the time the app was terminated.
 *
 *  @discussion         For apps that opt-in to state preservation and restoration, this is the first method invoked when your app is relaunched into
 *                      the background to complete some Bluetooth-related task. Use this method to synchronize your app's state with the state of the
 *                      Bluetooth system.
 *
 *  @seealso            CBCentralManagerRestoredStatePeripheralsKey;
 *  @seealso            CBCentralManagerRestoredStateScanServicesKey;
 *  @seealso            CBCentralManagerRestoredStateScanOptionsKey;
 *
 */
- (void)centralManager:(CBCentralManager *)central willRestoreState:(NSDictionary<NSString *, id> *)dict;

/*!
 *  @method centralManager:didDiscoverPeripheral:advertisementData:RSSI:
 *
 *  @param central              The central manager providing this update.
 *  @param peripheral           A <code>CBPeripheral</code> object.
 *  @param advertisementData    A dictionary containing any advertisement and scan response data.
 *  @param RSSI                 The current RSSI of <i>peripheral</i>, in dBm. A value of <code>127</code> is reserved and indicates the RSSI
 *                              was not available.
 *
 *  @discussion                 This method is invoked while scanning, upon the discovery of <i>peripheral</i> by <i>central</i>. A discovered peripheral must
 *                              be retained in order to use it; otherwise, it is assumed to not be of interest and will be cleaned up by the central manager. For
 *                              a list of <i>advertisementData</i> keys, see {@link CBAdvertisementDataLocalNameKey} and other similar constants.
 *
 *  @seealso                    CBAdvertisementData.h
 *
 */
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *, id> *)advertisementData RSSI:(NSNumber *)RSSI;

/*!
 *  @method centralManager:didConnectPeripheral:
 *
 *  @param central      The central manager providing this information.
 *  @param peripheral   The <code>CBPeripheral</code> that has connected.
 *
 *  @discussion         This method is invoked when a connection initiated by {@link connectPeripheral:options:} has succeeded.
 *
 */
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;

/*!
 *  @method centralManager:didFailToConnectPeripheral:error:
 *
 *  @param central      The central manager providing this information.
 *  @param peripheral   The <code>CBPeripheral</code> that has failed to connect.
 *  @param error        The cause of the failure.
 *
 *  @discussion         This method is invoked when a connection initiated by {@link connectPeripheral:options:} has failed to complete. As connection attempts do not
 *                      timeout, the failure of a connection is atypical and usually indicative of a transient issue.
 *
 */
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error;

/*!
 *  @method centralManager:didDisconnectPeripheral:error:
 *
 *  @param central      The central manager providing this information.
 *  @param peripheral   The <code>CBPeripheral</code> that has disconnected.
 *  @param error        If an error occurred, the cause of the failure.
 *
 *  @discussion         This method is invoked upon the disconnection of a peripheral that was connected by {@link connectPeripheral:options:}. If the disconnection
 *                      was not initiated by {@link cancelPeripheralConnection}, the cause will be detailed in the <i>error</i> parameter. Once this method has been
 *                      called, no more methods will be invoked on <i>peripheral</i>'s <code>CBPeripheralDelegate</code>.
 *
 */
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error;

@end

NS_ASSUME_NONNULL_END

CBManager

#import <CoreBluetooth/CBDefines.h>
#import <Foundation/Foundation.h>

NS_CLASS_AVAILABLE(N_A, 10_0)
CB_EXTERN_CLASS @interface CBManager : NSObject

- (instancetype)init NS_UNAVAILABLE;

/*!
 *  @enum CBManagerState
 *
 *  @discussion Represents the current state of a CBManager.
 *
 *  @constant CBManagerStateUnknown       State unknown, update imminent.
 *  @constant CBManagerStateResetting     The connection with the system service was momentarily lost, update imminent.
 *  @constant CBManagerStateUnsupported   The platform doesn't support the Bluetooth Low Energy Central/Client role.
 *  @constant CBManagerStateUnauthorized  The application is not authorized to use the Bluetooth Low Energy role.
 *  @constant CBManagerStatePoweredOff    Bluetooth is currently powered off.
 *  @constant CBManagerStatePoweredOn     Bluetooth is currently powered on and available to use.
 *
 */
typedef NS_ENUM(NSInteger, CBManagerState) {
    CBManagerStateUnknown = 0,
    CBManagerStateResetting,
    CBManagerStateUnsupported,
    CBManagerStateUnauthorized,
    CBManagerStatePoweredOff,
    CBManagerStatePoweredOn,
} NS_ENUM_AVAILABLE(NA, 10_0);

/*!
 *  @property state
 *
 *  @discussion The current state of the manager, initially set to <code>CBManagerStateUnknown</code>.
 *              Updates are provided by required delegate method {@link managerDidUpdateState:}.
 *
 */
@property(nonatomic, assign, readonly) CBManagerState state;

@end

上面两个类中有两个枚举，定义的就是蓝牙的状态，CBCentralManagerState已经被废弃了，被CBManagerState所替代，下面我们就对比看一下。

/*!
 *  @enum CBCentralManagerState
 *
 *  @discussion Represents the current state of a CBCentralManager.
 *
 *  @constant CBCentralManagerStateUnknown       State unknown, update imminent.
 *  @constant CBCentralManagerStateResetting     The connection with the system service was momentarily lost, update imminent.
 *  @constant CBCentralManagerStateUnsupported   The platform doesn't support the Bluetooth Low Energy Central/Client role.
 *  @constant CBCentralManagerStateUnauthorized  The application is not authorized to use the Bluetooth Low Energy Central/Client role.
 *  @constant CBCentralManagerStatePoweredOff    Bluetooth is currently powered off.
 *  @constant CBCentralManagerStatePoweredOn     Bluetooth is currently powered on and available to use.
 *
 */
typedef NS_ENUM(NSInteger, CBCentralManagerState) {
    CBCentralManagerStateUnknown = CBManagerStateUnknown,
    CBCentralManagerStateResetting = CBManagerStateResetting,
    CBCentralManagerStateUnsupported = CBManagerStateUnsupported,
    CBCentralManagerStateUnauthorized = CBManagerStateUnauthorized,
    CBCentralManagerStatePoweredOff = CBManagerStatePoweredOff,
    CBCentralManagerStatePoweredOn = CBManagerStatePoweredOn,
} NS_DEPRECATED(NA, NA, 5_0, 10_0, "Use CBManagerState instead");

/*!
 *  @enum CBManagerState
 *
 *  @discussion Represents the current state of a CBManager.
 *
 *  @constant CBManagerStateUnknown       State unknown, update imminent.
 *  @constant CBManagerStateResetting     The connection with the system service was momentarily lost, update imminent.
 *  @constant CBManagerStateUnsupported   The platform doesn't support the Bluetooth Low Energy Central/Client role.
 *  @constant CBManagerStateUnauthorized  The application is not authorized to use the Bluetooth Low Energy role.
 *  @constant CBManagerStatePoweredOff    Bluetooth is currently powered off.
 *  @constant CBManagerStatePoweredOn     Bluetooth is currently powered on and available to use.
 *
 */
typedef NS_ENUM(NSInteger, CBManagerState) {
    CBManagerStateUnknown = 0,
    CBManagerStateResetting,
    CBManagerStateUnsupported,
    CBManagerStateUnauthorized,
    CBManagerStatePoweredOff,
    CBManagerStatePoweredOn,
} NS_ENUM_AVAILABLE(NA, 10_0);

2. 代码实现

下面我们就直接看一下代码实现。

#import "JJBluetoothVC.h"
#import <CoreBluetooth/CoreBluetooth.h>

@interface JJBluetoothVC () <CBCentralManagerDelegate>

@property (nonatomic, strong) CBCentralManager *manager;

@end

@implementation JJBluetoothVC

#pragma mark - Override Base Function

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor lightTextColor];
    
    self.manager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}

- (void)dealloc
{
    self.manager = nil;
}

#pragma mark - CBCentralManagerDelegate

- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
    NSString *message = nil;
    
    switch (central.state) {
        case 0:
            message = @"状态未知，即将更新。";
            break;
        case 1:
            message = @"与系统服务的连接暂时丢失，即将更新";
            break;
        case 2:
            message = @"该平台不支持蓝牙低功耗中央/客户端角色。";
            break;
        case 3:
            message = @"该平台未授权使用蓝牙低功耗中央/客户端角色。";
            break;
        case 4:
            message = @"蓝牙关闭";
            break;
        case 5:
            message = @"蓝牙打开";
            break;
            
        default:
            break;
    }
    
    if (message && message.length > 0) {
        NSLog(@"message = %@", message);
    }

}
@end

下面看输出结果

2017-08-07 11:46:33.320425+0800 JJOC[8064:3233207] message = 蓝牙关闭

后记

未完，待续~~~~

立秋了