iOS开发之蓝牙通讯

iOS开发之蓝牙通讯

一、引言

        蓝牙是设备近距离通信的一种方便手段,在iPhone引入蓝牙4.0后,设备之间的通讯变得更加简单。相关的蓝牙操作由专门的CoreBluetooth.framework进行统一管理。通过蓝牙进行通讯交互分为两方,一方为中心设备central,一方为外设peripheral,外设通过广播的方式向外发送信息,中心设备检索到外设发的广播信息,可以进行配对连接,进而进行数据交互。

二、中心设备CBCentralManager

        CBCentralManager是管理中心设备的管理类,其中重要方法如下:

//设置中心设备代理
@property(assign, nonatomic, nullable) id<CBCentralManagerDelegate> delegate;
//中心设备当前状态
@property(readonly) CBCentralManagerState state;
//中心设备是否正在扫描
@property(readonly) BOOL isScanning NS_AVAILABLE(NA, 9_0);

其中state是一个枚举,有关蓝牙是否可用的状态如下:

typedef NS_ENUM(NSInteger, CBCentralManagerState) {
        //状态未知
    CBCentralManagerStateUnknown = 0,
    //连接断开 即将重置
    CBCentralManagerStateResetting,
    //该平台不支持蓝牙
    CBCentralManagerStateUnsupported,
    //未授权蓝牙使用 hovertree.com
    CBCentralManagerStateUnauthorized,
    //蓝牙关闭
    CBCentralManagerStatePoweredOff,
    //蓝牙正常开启
    CBCentralManagerStatePoweredOn,
};

下面这些方法用于初始化管理中心:

//初始化方法
//设置的代理需要遵守CBCentralManagerDelegate协议
//queue可以设置蓝牙扫描的线程 传入nil则为在主线程中进行
- (instancetype)initWithDelegate:(nullable id<CBCentralManagerDelegate>)delegate
                           queue:(nullable dispatch_queue_t)queue;
//此方法同上 在options字典中用于进行一些管理中心的初始化属性设置
//字典中支持的键值如下 http://www.cnblogs.com/roucheng/
/*
NSString * const CBCentralManagerOptionShowPowerAlertKey 对应一个NSNumber类型的bool值,用于设置是否在关闭蓝牙时弹出用户提示
NSString * const CBCentralManagerOptionRestoreIdentifierKey 对应一个NSString对象,设置管理中心的标识符ID
*/
- (instancetype)initWithDelegate:(nullable id<CBCentralManagerDelegate>)delegate
                           queue:(nullable dispatch_queue_t)queue
                         options:(nullable NSDictionary<NSString *, id> *)options;
//根据获取所有已知设备
- (NSArray<CBPeripheral *> *)retrievePeripheralsWithIdentifiers:(NSArray<NSUUID *> *)identifiers;
//根据服务id获取所有连接的设备 hovertree.com
- (NSArray<CBPeripheral *> *)retrieveConnectedPeripheralsWithServices:(NSArray<CBUUID *> *)serviceUUIDs;

在初始化管理中心完成后,会回调代理中的如下方法,我们必须实现如下方法:

//这个方法中可以获取到管理中心的状态
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;

如果上面方法中管理中心状态为蓝牙可用,可以通过下面方法开启扫描外设:

//serviceUUIDs用于扫描一个特点ID的外设 options用于设置一些扫描属性 键值如下
/*
//是否允许重复扫描 对应NSNumber的bool值,默认为NO,会自动去重
NSString *const CBCentralManagerScanOptionAllowDuplicatesKey;
//要扫描的设备UUID 数组 对应NSArray hovertree.com
NSString *const CBCentralManagerScanOptionSolicitedServiceUUIDsKey;
*/
- (void)scanForPeripheralsWithServices:(nullable NSArray<CBUUID *> *)serviceUUIDs options:(nullable NSDictionary<NSString *, id> *)options;
//停止扫描外设
- (void)stopScan;

扫描的结果会在如下代理方法中回掉:

//peripheral 扫描到的外设
//advertisementData是外设发送的广播数据
//RSSI 是信号强度 http://www.cnblogs.com/roucheng/
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *, id> *)advertisementData RSSI:(NSNumber *)RSSI;

扫描到外设后,通过下面方法可以连接一个外设:

/*
options中可以设置一些连接设备的初始属性键值如下
//对应NSNumber的bool值,设置当外设连接后是否弹出一个警告
NSString *const CBConnectPeripheralOptionNotifyOnConnectionKey;
//对应NSNumber的bool值,设置当外设断开连接后是否弹出一个警告
NSString *const CBConnectPeripheralOptionNotifyOnDisconnectionKey;
//对应NSNumber的bool值,设置当外设暂停连接后是否弹出一个警告 http://www.cnblogs.com/roucheng/
NSString *const CBConnectPeripheralOptionNotifyOnNotificationKey;
*/
- (void)connectPeripheral:(CBPeripheral *)peripheral options:(nullable NSDictionary<NSString *, id> *)options;
//取消一个外设的连接
- (void)cancelPeripheralConnection:(CBPeripheral *)peripheral;

调用过连接外设的方法后,会回掉如下代理方法:

//连接外设成功
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;
//连接外设失败
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error;
//断开外设连接
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error;

当管理中心恢复时会调用如下代理:

 1 //dict中会传入如下键值对 hovertree.com
 2 /*
 3 //恢复连接的外设数组
 4 NSString *const CBCentralManagerRestoredStatePeripheralsKey;
 5 //恢复连接的服务UUID数组
 6 NSString *const CBCentralManagerRestoredStateScanServicesKey;
 7 //恢复连接的外设扫描属性字典数组
 8 NSString *const CBCentralManagerRestoredStateScanOptionsKey;
 9 */
10 - (void)centralManager:(CBCentralManager *)central willRestoreState:(NSDictionary<NSString *, id> *)dict;

三、外设CBPeripheralManager

        从上面我们知道,中心设备是用来扫描周围的外设,两台设备的通讯中,必须有一个充当中心设备,一个充当外设,外设是由CBPeripheralManager进行管理,主要方法如下:

 1 //设置外设管理中心代理
 2 @property(assign, nonatomic, nullable) id<CBPeripheralManagerDelegate> delegate;
 3 //外设状态 枚举如中心设备
 4 @property(readonly) CBPeripheralManagerState state;
 5 //是否正在发送广播
 6 @property(readonly) BOOL isAdvertising;
 7 //用户的授权状态
 8 + (CBPeripheralManagerAuthorizationStatus)authorizationStatus;
 9 //初始化并设置代理 参数的具体含义与中心设备管理中心
10 - (instancetype)initWithDelegate:(nullable id<CBPeripheralManagerDelegate>)delegate
11                            queue:(nullable dispatch_queue_t);
12 - (instancetype)initWithDelegate:(nullable id<CBPeripheralManagerDelegate>)delegate
13                            queue:(nullable dispatch_queue_t)queue
14                          options:(nullable NSDictionary<NSString *, id> *)options;
15 //开始发送广播 hovertree.com  何问起
16 //advertisementData中可以发送的数据有约定 如下
17 /*
18 对应设置NSString类型的广播名
19 NSString *const CBAdvertisementDataLocalNameKey;
20 外设制造商的NSData数据
21 NSString *const CBAdvertisementDataManufacturerDataKey;
22 外设制造商的CBUUID数据
23 NSString *const CBAdvertisementDataServiceDataKey;
24 服务的UUID与其对应的服务数据字典数组
25 NSString *const CBAdvertisementDataServiceUUIDsKey;
26 附加服务的UUID数组
27 NSString *const CBAdvertisementDataOverflowServiceUUIDsKey;
28 外设的发送功率 NSNumber类型
29 NSString *const CBAdvertisementDataTxPowerLevelKey;
30 外设是否可以连接
31 NSString *const CBAdvertisementDataIsConnectable;
32 服务的UUID数组
33 NSString *const CBAdvertisementDataSolicitedServiceUUIDsKey;
34 */
35 - (void)startAdvertising:(nullable NSDictionary<NSString *, id> *)advertisementData;
36 //停止发送广播
37 - (void)stopAdvertising;
38 //设置一个连接的具体central设备的延时 枚举如下
39 /*
40 typedef NS_ENUM(NSInteger, CBPeripheralManagerConnectionLatency) {
41     CBPeripheralManagerConnectionLatencyLow = 0,
42     CBPeripheralManagerConnectionLatencyMedium,
43     CBPeripheralManagerConnectionLatencyHigh
44 } NS_ENUM_AVAILABLE(NA, 6_0);
45 */
46 - (void)setDesiredConnectionLatency:(CBPeripheralManagerConnectionLatency)latency forCentral:(CBCentral *)central;
47 //添加一个服务 http://www.cnblogs.com/roucheng/
48 - (void)addService:(CBMutableService *)service;
49 //移除一个服务
50 - (void)removeService:(CBMutableService *)service;
51 //移除所有服务
52 - (void)removeAllServices;
53 //响应中心设备的读写请求
54 - (void)respondToRequest:(CBATTRequest *)request withResult:(CBATTError)result;
55 //更新一个连接中心设备的订阅特征值
56 - (BOOL)updateValue:(NSData *)value forCharacteristic:(CBMutableCharacteristic *)characteristic onSubscribedCentrals:(nullable NSArray<CBCentral *> *)centrals;

外设代理的相关方法如下:

 1 //这个方法是必须实现的 状态可用后可以发送广播
 2 - (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral;
 3 //连接回复时调用的方法 和centralManager类似
 4 - (void)peripheralManager:(CBPeripheralManager *)peripheral willRestoreState:(NSDictionary<NSString *, id> *)dict;
 5 //开始发送广播时调用的方法
 6 - (void)peripheralManagerDidStartAdvertising:(CBPeripheralManager *)peripheral error:(nullable NSError *)error;
 7 //添加服务调用的回调
 8 - (void)peripheralManager:(CBPeripheralManager *)peripheral didAddService:(CBService *)service error:(nullable NSError *)error;
 9 //当一个central设备订阅一个特征值时调用的方法
10 - (void)peripheralManager:(CBPeripheralManager *)peripheral central:(CBCentral *)central didSubscribeToCharacteristic:(CBCharacteristic *)characteristic;
11 //取消订阅一个特征值时调用的方法
12 - (void)peripheralManager:(CBPeripheralManager *)peripheral central:(CBCentral *)central didUnsubscribeFromCharacteristic:(CBCharacteristic *)characteristic;
13 //收到读请求时触发的方法 何问起 hovertree.com
14 - (void)peripheralManager:(CBPeripheralManager *)peripheral didReceiveReadRequest:(CBATTRequest *)request;
15 //收到写请求时触发的方法
16 - (void)peripheralManager:(CBPeripheralManager *)peripheral didReceiveWriteRequests:(NSArray<CBATTRequest *> *)requests;
17 //外设准备更新特征值时调用的方法
18 - (void)peripheralManagerIsReadyToUpdateSubscribers:(CBPeripheralManager *)peripheral;

四、中心设备与外设对象CBCentral与CBPeripheral

        上面介绍了中心设备管理类与外设管理类,这些类用于将设备连接建立起来,器具的数据交换的服务和一些信息则是在对应的设备对象中。

1、中心设备 CBCentral属性与方法

//设备UUID
@property(readonly, nonatomic) NSUUID *identifier;
//中心设备最大接收的数据长度
@property(readonly, nonatomic) NSUInteger maximumUpdateValueLength;

2、外设CAPeripheral属性与方法

        外设对象要比中心对象复杂的多,当centralManager连接到外设后,需要通过外设对象的代理方法进行数据交互,其中主要方法属性如下:

 1 //设置代理
 2 @property(assign, nonatomic, nullable) id<CBPeripheralDelegate> delegate;
 3 //外设name
 4 @property(retain, readonly, nullable) NSString *name;
 5 //信号强度 http://www.cnblogs.com/roucheng/
 6 @property(retain, readonly, nullable) NSNumber *RSSI NS_DEPRECATED(NA, NA, 5_0, 8_0);
 7 //外设状态
 8 /*
 9 typedef NS_ENUM(NSInteger, CBPeripheralState) {
10     CBPeripheralStateDisconnected = 0,//未连接
11     CBPeripheralStateConnecting,//正在链接
12     CBPeripheralStateConnected,//已经连接
13     CBPeripheralStateDisconnecting NS_AVAILABLE(NA, 9_0),//正在断开连接
14 } NS_AVAILABLE(NA, 7_0);
15 */
16 @property(readonly) CBPeripheralState state;
17 //所有的服务数组
18 @property(retain, readonly, nullable) NSArray<CBService *> *services;
19 //获取当前信号强度
20 - (void)readRSSI;
21 //根据服务UUID寻找服务对象
22 - (void)discoverServices:(nullable NSArray<CBUUID *> *)serviceUUIDs;
23 //在服务对象UUID数组中寻找特定服务
24 - (void)discoverIncludedServices:(nullable NSArray<CBUUID *> *)includedServiceUUIDs forService:(CBService *)service;
25 //在一个服务中寻找特征值
26 - (void)discoverCharacteristics:(nullable NSArray<CBUUID *> *)characteristicUUIDs forService:(CBService *)service;
27 //从一个特征中读取数据
28 - (void)readValueForCharacteristic:(CBCharacteristic *)characteristic;
29 //写数据的最大长度 hovertree.com  何问起
30 //type枚举如下
31 /*
32 typedef NS_ENUM(NSInteger, CBCharacteristicWriteType) {
33     CBCharacteristicWriteWithResponse = 0,//写数据并且接收成功与否回执
34     CBCharacteristicWriteWithoutResponse,//写数据不接收回执
35 };
36 */
37 - (NSUInteger)maximumWriteValueLengthForType:(CBCharacteristicWriteType)type NS_AVAILABLE(NA, 9_0);
38 //向某个特征中写数据
39 - (void)writeValue:(NSData *)data forCharacteristic:(CBCharacteristic *)characteristic type:(CBCharacteristicWriteType)type;
40 //为制定的特征值设置监听通知
41 - (void)setNotifyValue:(BOOL)enabled forCharacteristic:(CBCharacteristic *)characteristic;
42 //寻找特征值的描述
43 - (void)discoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic;
44 //读取特征的描述值
45 - (void)readValueForDescriptor:(CBDescriptor *)descriptor;
46 //写特征的描述值
47 - (void)writeValue:(NSData *)data forDescriptor:(CBDescriptor *)descriptor;
View Code

外设的代理方法如下:

 1 //外设名称更改时回调的方法
 2 - (void)peripheralDidUpdateName:(CBPeripheral *)peripheral NS_AVAILABLE(NA, 6_0);
 3 //外设服务变化时回调的方法
 4 - (void)peripheral:(CBPeripheral *)peripheral didModifyServices:(NSArray<CBService *> *)invalidatedServices NS_AVAILABLE(NA, 7_0);
 5 //信号强度改变时调用的方法
 6 - (void)peripheralDidUpdateRSSI:(CBPeripheral *)peripheral error:(nullable NSError *)error NS_DEPRECATED(NA, NA, 5_0, 8_0);
 7 //读取信号强度回调的方法 柯乐义 keleyi.com
 8 - (void)peripheral:(CBPeripheral *)peripheral didReadRSSI:(NSNumber *)RSSI error:(nullable NSError *)error NS_AVAILABLE(NA, 8_0);
 9 //发现服务时调用的方法
10 - (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(nullable NSError *)error;
11 //在服务中发现子服务回调的方法
12 - (void)peripheral:(CBPeripheral *)peripheral didDiscoverIncludedServicesForService:(CBService *)service error:(nullable NSError *)error;
13 //发现服务的特征值后回调的方法
14 - (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(nullable NSError *)error;
15 //特征值更新时回调的方法
16 - (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(nullable NSError *)error;
17 //向特征值写数据时回调的方法
18  - (void)peripheral:(CBPeripheral *)peripheral didWriteValueForCharacteristic:(CBCharacteristic *)characteristic error:(nullable NSError *)error;
19  //特征值的通知设置改变时触发的方法
20  - (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(nullable NSError *)error;
21  //发现特征值的描述信息触发的方法
22  - (void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(nullable NSError *)error;
23  //特征的描述值更新时触发的方法
24  - (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(CBDescriptor *)descriptor error:(nullable NSError *)error;
25  //写描述信息时触发的方法
26  - (void)peripheral:(CBPeripheral *)peripheral didWriteValueForDescriptor:(CBDescriptor *)descriptor error:(nullable NSError *)error;
View Code

五、服务对象CBService

    服务对象是用来管理外设提供的一些数据服务的,其中属性如下:

//对应的外设
@property(assign, readonly, nonatomic) CBPeripheral *peripheral;
//是否是初等服务
@property(readonly, nonatomic) BOOL isPrimary;
//包含的自服务 http://www.cnblogs.com/roucheng/
@property(retain, readonly, nullable) NSArray<CBService *> *includedServices;
//服务中的特征值
@property(retain, readonly, nullable) NSArray<CBCharacteristic *> *characteristics;

六、服务的特征值CBCharacteristic

        通过绑定服务中的特征值来进行数据的读写操作,其中属性如下:

//对应的服务对象
@property(assign, readonly, nonatomic) CBService *service;
//特征值的属性 枚举如下
/*
typedef NS_OPTIONS(NSUInteger, CBCharacteristicProperties) {
    CBCharacteristicPropertyBroadcast,//允许广播特征
    CBCharacteristicPropertyRead,//可读属性
    CBCharacteristicPropertyWriteWithoutResponse,//可写并且接收回执
    CBCharacteristicPropertyWrite,//可写属性
    CBCharacteristicPropertyNotify,//可通知属性
    CBCharacteristicPropertyIndicate,//可展现的特征值
    CBCharacteristicPropertyAuthenticatedSignedWrites,//允许签名的特征值写入
    CBCharacteristicPropertyExtendedProperties,
    CBCharacteristicPropertyNotifyEncryptionRequired,
    CBCharacteristicPropertyIndicateEncryptionRequired
};
*/
@property(readonly, nonatomic) CBCharacteristicProperties properties;
//特征值的数据 http://www.cnblogs.com/roucheng/
@property(retain, readonly, nullable) NSData *value;
//特征值的描述
@property(retain, readonly, nullable) NSArray<CBDescriptor *> *descriptors;
//是否是当前广播的特征
@property(readonly) BOOL isBroadcasted;
//是否是正在通知的特征
@property(readonly) BOOL isNotifying;

七、读写请求对象CBATTRequest

        服务对象是外设向中心设备提供的相关数据服务,获取到相应服务后,中心设备可以进行读写请求,读写对象属性如下:

//对应的中心设备
@property(readonly, nonatomic) CBCentral *central;
//对应的特征值
@property(readonly, nonatomic) CBCharacteristic *characteristic;
//读写数据值
@property(readwrite, copy, nullable) NSData *value;

http://www.cnblogs.com/roucheng/p/texiao.html

本文小结:

  • iOS开发之蓝牙通讯
  • 一、引言
  • 二、中心设备CBCentralManager
  • 三、外设CBPeripheralManager
  • 四、中心设备与外设对象CBCentral与CBPeripheral
  • 1、中心设备 CBCentral属性与方法
  • 2、外设CAPeripheral属性与方法
  • 五、服务对象CBService
  • 六、服务的特征值CBCharacteristic
  • 七、读写请求对象CBATTRequest

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