不要让你的梦想 只停留在梦里

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:

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);}

好像有头大象在吸水。然后再去了芦笛岩，