iOS蓝牙

来源：互联网发布：翻墙违法吗知乎编辑：程序博客网时间：2024/05/20 18:49

一.概念
1.引用的框架是CoreBluetooth,在iphone4s开始支持,专门用于与BLE设备通讯（因为它的API都是基于BLE的）。这个不需要MFI，并且现在很多蓝牙设备都支持4.0,所以也是在IOS比较推荐的一种开发方法。
2.CoreBluetooth框架的核心其实是两个东西，peripheral和central, 可以理解成外围和中心。如下图所示:
这里写图片描述

3.特征和服务
有个概念有必要先说明一下。什么是服务和特征呢(service and characteristic)?
每个蓝牙4.0的设备都是通过服务和特征来展示自己的，一个设备必然包含一个或多个服务，每个服务下面又包含若干个特征。特征是与外界交互的最小单位。比如说，一台蓝牙4.0设备，用特征A来描述自己的出厂信息，用特征B来与收发数据等。
服务和特征都是用UUID来唯一标识的，UUID的概念如果不清楚请自行google,国际蓝牙组织为一些很典型的设备(比如测量心跳和血压的设备)规定了标准的service UUID.
4.作为一个中心要实现完整的通讯，一般要经过这样几个步骤：
建立中心角色—扫描围（discover）—连接外围(connect)—扫描外围中的服务和特征(discover)—与外围做数据交互(explore and interact)—断开连接(disconnect)。

二.代码实现.

1.外围工程类代码实现如下:

/**创建一个外围类*/#import "ViewController.h"#import <CoreBluetooth/CoreBluetooth.h>/**服务端的UUID*/#define kServiceUUID  @"3AF70026-AB81-4EF2-B90B-9C482B4812F1"/**特征端的UUID*/#define kCharacteristicUUID  @"2F5A22C7-7AB5-446A-9F94-4E9B924BE508"@interface ViewController ()<CBPeripheralManagerDelegate>{    /**1.创建一个外围管理者*/    CBPeripheralManager* _manager;    /**2.创建服务端*/    CBMutableService* _service;    /**3.创建一个特征端*/    CBMutableCharacteristic* _characteristic;}@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    /**4.实例化一个特征类*/    _manager = [[CBPeripheralManager alloc] initWithDelegate:self queue:nil];}- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{    NSLog(@"发现外设");}/**5.检测中央设备状态*/- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral{    /**5.1.如果不是打开的,打印蓝牙关闭,直接返回,调用开始中心服务,CBCentralManagerStatePoweredOn,表示蓝牙打开*/    if (peripheral.state != CBCentralManagerStatePoweredOn){        NSLog(@"蓝牙关闭");        return;    }    //开始中心服务    [self startService];}/**6.开始中心服务*/- (void)startService{    /**6.1通过uuid创建一个特征,kCharacteristicUUID特征类的UUID,UUID是唯一标识,通过唯一标识可以找到设备*/    CBUUID* characteristicUUID = [CBUUID UUIDWithString:kCharacteristicUUID];    /**6.2第一个参数uuid，第二个参数决定这个特征怎么去用，第三个是是否加密*/    _characteristic = [[CBMutableCharacteristic alloc] initWithType:characteristicUUID properties:CBCharacteristicPropertyNotify value:nil permissions:CBAttributePermissionsReadable];    /**6.3创建一个服务uuid*/    CBUUID* serviceUUID = [CBUUID UUIDWithString:kServiceUUID];    /**6.4通过uuid创建服务*/    _service = [[CBMutableService alloc] initWithType:serviceUUID primary:YES];    /**6.5给服务设置特征*/    [_service setCharacteristics:@[_characteristic]];    /**6.6使用这个服务,添加到管理者中*/    [_manager addService:_service];}/**7.添加服务后的回调*/- (void)peripheralManager:(CBPeripheralManager *)peripheral didAddService:(CBService *)service error:(NSError *)error{    /**7.1如果没有错误，就可以开始广播服务了*/    if (error == nil) {        [_manager startAdvertising:@{                                     CBAdvertisementDataLocalNameKey:@"PKServer",                                     CBAdvertisementDataServiceUUIDsKey:@[[CBUUID UUIDWithString:kServiceUUID]]                                     }];        //[_manager updateValue:[@"pk" dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:_characteristic onSubscribedCentrals:]    }}/**8.有人连接成功后调用*/- (void)peripheralManager:(CBPeripheralManager *)peripheral central:(CBCentral *)central didSubscribeToCharacteristic:(CBCharacteristic *)characteristic{    NSLog(@"连接成功");    [_manager updateValue:[@"pk" dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:_characteristic onSubscribedCentrals:@[central]];}/**9.断开调用*/- (void)peripheralManager:(CBPeripheralManager *)peripheral central:(CBCentral *)central didUnsubscribeFromCharacteristic:(CBCharacteristic *)characteristic{    NSLog(@"断开");}@end

 2.中心工程类代码实现如下:

#import "ViewController.h"#import <CoreBluetooth/CoreBluetooth.h>/**服务UUID*/#define kServiceUUID  @"3AF70026-AB81-4EF2-B90B-9C482B4812F1"/**特征UUID*/#define kCharacteristicUUID  @"2F5A22C7-7AB5-446A-9F94-4E9B924BE508"@interface ViewController ()<CBCentralManagerDelegate, CBPeripheralDelegate>{    CBCentralManager* _manager;    NSMutableData* _data;    CBPeripheral* _peripheral;}@end@implementation ViewController- (void)viewDidLoad {    /**创建一个中央*/    _manager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];}- (void)centralManagerDidUpdateState:(CBCentralManager *)central{    if (central.state != CBCentralManagerStatePoweredOn) {        NSLog(@"蓝牙未打开");        return;    }    /**开始寻找所有的服务*/    [_manager scanForPeripheralsWithServices:@[[CBUUID UUIDWithString:kServiceUUID]] options:@{                                                CBCentralManagerScanOptionAllowDuplicatesKey:@YES                                                                                               }];}/**寻找到服务*/- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{    /**停止寻找*/    [_manager stopScan];    if (_peripheral != peripheral) {        _peripheral = peripheral;        /**开始连接周边*/        [_manager connectPeripheral:_peripheral options:nil];    }}/**连接周边成功*/- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral{    [_data setLength:0];    _peripheral.delegate = self;    /**连接周边服务*/    [_peripheral discoverServices:@[[CBUUID UUIDWithString:kServiceUUID]]];}/**连接周边失败*/- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{    NSLog(@"连接失败");}/**连接周边服务*/- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{    if (error) {        NSLog(@"错误的服务");        return;    }    /**遍历服务*/    for (CBService* service in peripheral.services) {        if ([service.UUID isEqual:[CBUUID UUIDWithString:kServiceUUID]]) {            /**连接特征*/            [_peripheral discoverCharacteristics:@[[CBUUID UUIDWithString:kCharacteristicUUID]] forService:service];        }    }}/**发现特征*/- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error{    if (error) {        NSLog(@"连接特征失败");        return;    }    /**遍历特征*/    if ([service.UUID isEqual:[CBUUID UUIDWithString:kServiceUUID]]) {        for (CBCharacteristic* characteristic in service.characteristics) {            if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:kCharacteristicUUID]]) {                /**开始监听特征*/                [_peripheral setNotifyValue:YES forCharacteristic:characteristic];            }        }    }}/**监听到特征值更新*/- (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{    if (error) {        NSLog(@"特征值出错");        return;    }    if (![characteristic.UUID isEqual:[CBUUID UUIDWithString:kCharacteristicUUID]]) {        return;    }    /**如果有新值，读取新的值*/    if (characteristic.isNotifying) {        [peripheral readValueForCharacteristic:characteristic];    }}/**收到新值*/- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{    NSString* str = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding];    NSLog(@"%@", str);}

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