CoreBluetooth 使用
东门玺
CoreBluetooth是基于蓝牙ble技术实现的,现在的智能手环手表都使用了低功耗蓝牙技术
CoreBluetooth场景中蓝牙对象分为两种:
1.中心设备(CBCentralManager * cbcManager):中心设备负责扫描接收广播,连接外设设备,向外设设备进行读写操作
1.外设设备(CBPeripheral * peripheral):向外发送广播,向中心设备读写操作
注意:一个设备既可以是中心设备,又可以是外设设备,但是不能同时是中心设备和外设设备,同一时间,只能扮演一种角色
基础知识介绍:
CBPeripheral
//CBPeripheral 属性
//外设状态
typedef NS_ENUM(NSInteger, CBPeripheralState) {
CBPeripheralStateDisconnected = 0, // 没有连接
CBPeripheralStateConnecting,//正在连接
CBPeripheralStateConnected,//已经连接
CBPeripheralStateDisconnecting NS_AVAILABLE(10_13, 9_0),
} NS_AVAILABLE(10_9, 7_0);
@interface CBPeripheral : CBPeer
@property(weak, nonatomic, nullable) id<CBPeripheralDelegate> delegate;
@property(retain, readonly, nullable) NSString *name;//外设名字
@property(retain, readonly, nullable) NSNumber *RSSI;//信号强度
@property(readonly) CBPeripheralState state;//外设状态
@property(retain, readonly, nullable) NSArray<CBService *> *services;//外设包含的服务(每个服务里面可能包含多个特征)
@property(readonly) BOOL canSendWriteWithoutResponse;//判断读写性
// CBPeripheral 常用方法
//查找外设包含的服务 serviceUUIDs 为nil 则查找该外设包含的所有服务 执行该方法会出发代理方法
- (void)discoverServices:(nullable NSArray<CBUUID *> *)serviceUUIDs;
// 扫描 特征的描述,执行该方法会出发代理方法
- (void)discoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic;
//扫描服务里包含的服务,执行该方法会出发代理方法
- (void)discoverIncludedServices:(nullable NSArray<CBUUID *> *)includedServiceUUIDs forService:(CBService *)service;
//扫描服务包含的特征,执行该方法会出发代理方法
- (void)discoverCharacteristics:(nullable NSArray<CBUUID *> *)characteristicUUIDs forService:(CBService *)service;
//读取 某特征的数据
- (void)readValueForCharacteristic:(CBCharacteristic *)characteristic;
//读取描述的值
- (void)readValueForDescriptor:(CBDescriptor *)descriptor;(CBCharacteristicWriteType)type;
//通过特征写入数据
- (void)writeValue:(NSData *)data forCharacteristic:(CBCharacteristic *)characteristic type:
//通过描述写入数据
- (void)writeValue:(NSData *)data forDescriptor:(CBDescriptor *)descriptor;
//设置通知
- (void)setNotifyValue:(BOOL)enabled forCharacteristic:(CBCharacteristic *)characteristic;
//代理方法
//扫描外设服务触发该代理,如果找打服务 可以在这里调用discoverCharacteristics 方法查找该服务的特征
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error;
//扫描服务包含的服务(服务里面可能会包含服务)
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverIncludedServicesForService:(CBService *)service error:(NSError *)error;
//查找服务的特征 ,一个服务可能有多个特征,一个特征可能有多个属性,CBCharacteristic是一个枚举值
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(nonnull CBService *)service error:(nullable NSError *)error;
//接收通知代理
-(void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error;
//读取Characteristic 中的值,调用readValueForCharacteristic 方法会触发该代理,需要在该代理方法里面获取具体的数据
-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error;
//向 CBCharacteristic 写入数据的回调
-(void)peripheral:(CBPeripheral *)peripheral didWriteValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error;
CBCentralManager
//中心设备的状态 创建中心设备的时候 会触发代理,在代理里面判断中心设备状态,在状态为CBManagerStatePoweredOn的时候可以开始扫描广播
typedef NS_ENUM(NSInteger, CBCentralManagerState) {
CBCentralManagerStateUnknown = CBManagerStateUnknown,//未知
CBCentralManagerStateResetting = CBManagerStateResetting,//正在重置
CBCentralManagerStateUnsupported = CBManagerStateUnsupported,//不支持
CBCentralManagerStateUnauthorized = CBManagerStateUnauthorized,
CBCentralManagerStatePoweredOff = CBManagerStatePoweredOff,//没有打开蓝牙
CBCentralManagerStatePoweredOn = CBManagerStatePoweredOn,//蓝牙以打开,可以扫描广播
} NS_DEPRECATED(10_7, 10_13, 5_0, 10_0, "Use CBManagerState instead");
@interface CBCentralManager : CBManager
@property(nonatomic, weak, nullable) id<CBCentralManagerDelegate> delegate;
@property(nonatomic, assign, readonly) BOOL isScanning ;//判断蓝牙是否正在扫描广播
//蓝牙中心设备初始化方法,需要指定 delegate 并实现代理方法
- (instancetype)initWithDelegate:(nullable id<CBCentralManagerDelegate>)delegate
queue:(nullable dispatch_queue_t)queue;
// 常用方法
//通过服务 ID 来扫描外设
- (void)scanForPeripheralsWithServices:(nullable NSArray<CBUUID *> *)serviceUUIDs options:(nullable NSDictionary<NSString *, id> *)options;
//连接外设
- (void)connectPeripheral:(CBPeripheral *)peripheral options:(nullable NSDictionary<NSString *, id> *)options;
//取消连接
- (void)cancelPeripheralConnection:(CBPeripheral *)peripheral;
//停止扫描
- (void)stopScan;
//通过 ID 数组查找外设
- (NSArray<CBPeripheral *> *)retrievePeripheralsWithIdentifiers:(NSArray<NSUUID *> *)identifiers NS_AVAILABLE(10_9, 7_0);
//通过 服务的UUID 数组查找外设
- (NSArray<CBPeripheral *>*)retrieveConnectedPeripheralsWithServices:(NSArray<CBUUID *> *)serviceUUIDs NS_AVAILABLE(10_9, 7_0);
// @protocol CBCentralManagerDelegate <NSObject> 代理方法
//中心设备开始扫描之后,每发现一个外设就会调用一次该方法,同一设备可能会被发现多次,扫描频率基本固定,外设发送的广播不一定每一个都能接收到,如果使用该方法获取广播数据的时候需要注意
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *, id> *)advertisementData RSSI:(NSNumber *)RSSI;
//中心设备连接上外设之后调用
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;
//连接失败调用
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error;
//断开连接
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error;
// 中心设备 状态改变的时候调用
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;
//中心设备状态重置的时候调用
- (void)centralManager:(CBCentralManager *)central willRestoreState:(NSDictionary<NSString *, id> *)dict;
连接过程: 外设设备向外广播,中心设备接收广播,广播包含了广播内容和外设的名字,信号强度等属性(IiOS 的CoreBluetooth框架不能从广播里面获取到 外设 MAC地址,所以不能使用MAC地址来区分外设). 扫描 -> 连接 ->扫描外设所包含的服务Services -> 扫描每一个服务所包含的特征Characteristics ->判断特征的属性CBCharacteristicProperties,根据需求保存对应属性的Characteristics,后面读/写的时候只能往可读/可写属性的特征里面写
CBCharacteristicProperties 是一个枚举
注意:一个特征可能同时拥有多个属性 :比如属性值为 0x02 & 0x08则该特性可读可写
typedef NS_OPTIONS(NSUInteger, CBCharacteristicProperties) {
CBCharacteristicPropertyBroadcast= 0x01,//广播属性
CBCharacteristicPropertyRead= 0x02,//可读属性
CBCharacteristicPropertyWriteWithoutResponse= 0x04,//无响应的写
CBCharacteristicPropertyWrite= 0x08,//写
CBCharacteristicPropertyNotify= 0x10,//通知
CBCharacteristicPropertyIndicate= 0x20,
CBCharacteristicPropertyAuthenticatedSignedWrites= 0x40,
CBCharacteristicPropertyExtendedProperties= 0x80,
CBCharacteristicPropertyNotifyEncryptionRequired= 0x100,
CBCharacteristicPropertyIndicateEncryptionRequired= 0x200
};
实际使用
1. CBCentralManager 中心设备方法使用
@interface XIXCBCenterManager : CBCentralManagerDelegate
@property (strong, nonatomic) CBCentralManager * cbcManager;
...
-(void)propertyInit{
...
//创建 cbcManager 对象,创建之后会调用 代理 返回 中心设备状态
self.cbcManager = [[CBCentralManager alloc]initWithDelegate:self queue:nil];
}
#pragma mark - CoreBlueToothDelegate
//蓝牙状态代理 蓝牙创建之后会调用一次
-(void)centralManagerDidUpdateState:(CBCentralManager *)central{
switch (central.state) {
case CBManagerStatePoweredOn: //蓝牙状态可用
NSLog(@"蓝牙已打开,可用,开始扫描");
//蓝牙状态可用的时候,开启扫描可用的蓝牙外设
[self.cbcManager scanForPeripheralsWithServices:nil options:nil];
[MBProgressHUD ShowMBToView:self.view withMessage:@"正在扫描设备..."];
break;
case CBManagerStateUnsupported:
[MBProgressHUD showError:@"蓝牙不可用"];
break;
default:{
[MBProgressHUD hideHUDForView:self.view];
UIAlertController * alertVC = [UIAlertController alertControllerWithTitle:nil message:@"请先开启蓝牙功能" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction * cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];
UIAlertAction * settingAction = [UIAlertAction actionWithTitle:@"去设置" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action){
[[UIApplication sharedApplication]openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
}];
[alertVC addAction:cancelAction];
[alertVC addAction:settingAction];
[self presentViewController:alertVC animated:YES completion:nil];
}
break;
}
}
/**
扫描到蓝牙外设后调用 ,每扫描到一个设备信息返回一次,判断返回的该蓝牙是否是已经被添加过的,如果被添加过,则替换数组中的该设备,如果没有添加过则添加到数组
@param central central
@param peripheral 扫描到的蓝牙外设
@param advertisementData 蓝牙外设的额外数据
@param RSSI 信号强度
*/
-(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(nonnull CBPeripheral *)peripheral advertisementData:(nonnull NSDictionary<NSString *,id> *)advertisementData RSSI:(nonnull NSNumber *)RSSI{
if (peripheral.name.length <= 0) return;
//获取外设广播包含的数据
NSData * adverData = advertisementData[@"kCBAdvDataManufacturerData"] ;
if(adverData != nil){
AdvertiseMentModel * advModel = [self.connect getAdvertisementData:adverData];
// 若果扫描到的外设已存在,则替换,如果不存在则添加,刷新列表
if (advModel) {
PeripheralModel * peripheralModel;
if (![self.perArray containsObject:peripheral]) {
[self.perArray addObject:peripheral];
peripheralModel = [[PeripheralModel alloc]initWithPeripheral:peripheral];
[self.deviceArray addObject:peripheralModel];
}
NSInteger index = [self.perArray indexOfObject:peripheral];
peripheralModel = self.deviceArray[index];
peripheralModel.advertisementModel = advModel;
[self.tableView reloadData];
}
}
}
// 使用列表展示外设,点击Cell 的时候,获取外设对象并连接
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
self.selectedPeriphalModel = self.resultList[indexPath.row];
NSDictionary * dic = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:CBConnectPeripheralOptionNotifyOnDisconnectionKey];
[self.cbcManager connectPeripheral:self.selectedPeriphalModel.periphal options:dic];
[MBProgressHUD ShowMBToView:self.view withMessage:@"正在连接设备..."];
//设置10s 的连接超时时间,连接超时则调用
// [self.cbcManager cancelPeripheralConnection:self.selectedPeriphalModel.periphal];取消连接
[self performSelector:@selector(connectTimeOut) withObject:nil afterDelay:10];
}
//连接成功调用代理
/**
连接外设成功后调用
@param central central
@param peripheral 连接成功的设备
*/
-(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral{
//没有超时则需要取消延迟 调用方法 同时停止扫描
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(connectTimeOut) object:nil];
[self.cbcManager stopScan];//停止扫描
[MBProgressHUD hideHUDForView:self.view animated:YES];
}
/**
连接失败调用
@param central central
@param peripheral 连接的设备
@param error 错误原因
*/
-(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{
[MBProgressHUD hideHUDForView:self.view animated:YES];
[MBProgressHUD showError:@"连接失败"];
}
//断开连接
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error{
[MBProgressHUD hideHUDForView:self.view animated:NO];
}
2. CBPeripheral 外设设备方法使用
#define CHARACTER_UUID_WRITE @"5E9BF2A8-F93F-4481-A67E-3B2F4A07891A"
#define CHARACTER_UUID_NOTI @"8AC32D3F-5CB9-4D44-BEC2-EE689169F626"
@property (strong, nonatomic) CBPeripheral * peripheral;
//保存可写的特征,写数据的时候用这个特征写入数据
@property (strong, nonatomic) CBCharacteristic * writeCharacter;
//连接上外设之后 调用 discoverServices 方法,查找该外设所包含的服务
[self.peripheral discoverServices:nil];
//写入数据
[self.peripheral writeValue:data forCharacteristic:self.writeCharacter type:CBCharacteristicWriteWithResponse];
#pragma mark - CBPeripheralDelegate
/**
查找蓝牙代理的服务 一个蓝牙 外设可能有多个服务
@param peripheral peripheral
@param error 错误信息
*/
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
// NSString * UUID_str = [peripheral.identifier UUIDString];
// NSLog(@"UUID:%@",UUID_str);
if (error) {
NSLog(@"查找蓝牙服务出错");
return;
}
//开始遍历查找服务 查找每个服务的特征
for (CBService * service in peripheral.services) {
//如果知道特征的 UUID 可以在第一个参数传入 UUID数组
NSLog(@"服务CBUUID:%@",service.UUID.UUIDString);
[self.peripheral discoverCharacteristics:nil forService:service];
}
}
//扫描服务包含的服务
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverIncludedServicesForService:(CBService *)service error:(NSError *)error{
if (error) {
NSLog(@"扫描服务内部的服务失败");
return;
}
NSArray * services = service.includedServices;
for (CBService * service in services) {
//如果知道特征的 UUID 可以在第一个参数传入 UUID数组
[peripheral discoverCharacteristics:nil forService:service];
}
}
//查找服务的特征 ,一个服务可能有多个特征,一个特征可能有多个属性,CBCharacteristic是一个枚举值
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(nonnull CBService *)service error:(nullable NSError *)error{
if(error){
NSLog(@"查找特征错误");
return;
}
for (CBCharacteristic * characteristic in service.characteristics) {
//这里开发的时候和硬件沟通 获取到了具体的 特征的 UUID
if([characteristic.UUID.UUIDString isEqualToString: CHARACTER_UUID_WRITE]){
self.writeCharacter = characteristic; // 这是可写属性,保存起来后面需要使用它来写数据
}else if([characteristic.UUID.UUIDString isEqualToString: CHARACTER_UUID_NOTI]){
//监听该特征,外设发送通知的时候才能收到数据
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
}
}
//接收通知代理
-(void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{
if (error) {
NSLog(@"错误:%@",error.localizedDescription);
return;
}
CBCharacteristicProperties properties = characteristic.properties;
if (properties & CBCharacteristicPropertyRead) {
//如果具备读特性,即可读取特性的 Value 值
[peripheral readValueForCharacteristic:characteristic];
}
}
//读取Characteristic 中的值
-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error{
if (error) {
NSLog(@"读取数据错误:%@",error.localizedDescription);
return;
}
NSData * dada = characteristic.value;
if (dada.length <= 0) {
return;
}
Byte * byteData = (Byte*)[dada bytes];
if (!(byteData[0] == 0x48 && byteData[1] == 0x65 &&byteData[2] == 0x6c &&byteData[3] == 0x6c)) {
NSLog(@"通知数据:%@",dada);
....
}
}
//写入数据的回调,返回写入成功失败结果
-(void)peripheral:(CBPeripheral *)peripheral didWriteValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error{
if (error) {
NSLog(@"写入数据失败");
}
}
中心设备就是主动去连接别的设备的设备,一般就是手机,外设就是发送广播,被连接的设备,一般就是手环或者包含蓝牙模块的硬件设备
CoreBlutooth已经把ble封装的很好,只需要顺着代理方法一步一步从扫描到连接到数据读写都可以完成
另外: 蓝牙广播的数据长度大小有限制,不能通过广播获取 外设MAC地址来区分,所以区分多个外设的话就需要在广播的kCBAdvDataManufacturerData字段的数据里面包含, advertisementData数据包含多个字段,大家可以在使用的时候打印看看,具体的字段对数据的类型也有限制,服务,特征,描述都是对应的uuid来唯一标识,如何知道UUID的话直接使用UUID能免去多层遍历
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