在上一节说了APP作为中心设备（central）连接到外设（peripheral），这一节主要讲将手机作为peripheral，给其他的central连接。
CoreBluetoothFramework.jpeg
还是这张图，central模式用的是左边的类，而perpheral模式用的是右边的类。
一、peripheral模式的流程
- 打开peripheralManager，设置peripheralManager的委托
- 创建characteristics，characteristics的description 创建service，把characteristics添加到service中，再把service添加到peripheralManager中
- 开启广播advertising
- 对central的操作进行响应
- 4.1 读characteristics请求
- 4.2 写characteristics请求
- 4.4 订阅和取消订阅characteristics
二、实现步骤
1.引入蓝牙库，引用CBPeripheralManagerDelegate，初始化管理者CBPeripheralManager
/*
和CBCentralManager类似，蓝牙设备打开需要一定时间，打开成功后会进入委托方法
- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral;
模拟器永远也不会得CBPeripheralManagerStatePoweredOn状态
*/
peripheralManager = [[CBPeripheralManager alloc]initWithDelegate:self queue:nil];
2.创建characterics,characterics的description,创建service,把characterics添加的service,再把service添加到perpheralManager中
在委托方法 - (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral中，当peripheral成功打开后，才可以配置service和characteristics。 这里创建的service和chara对象是CBMutableCharacteristic和CBMutableService。他们的区别就像NSArray和NSMutableArray区别类似。 我们先创建characteristics和description，description是characteristics的描述，描述分很多种， 这里不细说了，常用的就是CBUUIDCharacteristicUserDescriptionString。
#pragma mark -- CBPeripheralManagerDelegate
//peripheralManager状态改变
- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral{
switch (peripheral.state) {
//在这里判断蓝牙设别的状态 当开启了则可调用 setUp方法(自定义)
case CBPeripheralManagerStatePoweredOn:
NSLog(@"powered on");
[info setText:[NSString stringWithFormat:@"设备名%@已经打开，可以使用center进行连接",LocalNameKey]];
[self setUp];
break;
case CBPeripheralManagerStatePoweredOff:
NSLog(@"powered off");
[info setText:@"powered off"];
break;
default:
break;
}
}
蓝牙成功打开之后配置bluetooth的service
//配置bluetooch的
-(void)setUp{
//characteristics字段描述
CBUUID *CBUUIDCharacteristicUserDescriptionStringUUID = [CBUUID UUIDWithString:CBUUIDCharacteristicUserDescriptionString];
/*
可以通知的Characteristic
properties：CBCharacteristicPropertyNotify
permissions CBAttributePermissionsReadable
*/
CBMutableCharacteristic *notiyCharacteristic = [[CBMutableCharacteristic alloc]initWithType:[CBUUID UUIDWithString:notiyCharacteristicUUID] properties:CBCharacteristicPropertyNotify value:nil permissions:CBAttributePermissionsReadable];
/*
可读写的characteristics
properties：CBCharacteristicPropertyWrite | CBCharacteristicPropertyRead
permissions CBAttributePermissionsReadable | CBAttributePermissionsWriteable
*/
CBMutableCharacteristic *readwriteCharacteristic = [[CBMutableCharacteristic alloc]initWithType:[CBUUID UUIDWithString:readwriteCharacteristicUUID] properties:CBCharacteristicPropertyWrite | CBCharacteristicPropertyRead value:nil permissions:CBAttributePermissionsReadable | CBAttributePermissionsWriteable];
//设置description
CBMutableDescriptor *readwriteCharacteristicDescription1 = [[CBMutableDescriptor alloc]initWithType: CBUUIDCharacteristicUserDescriptionStringUUID value:@"name"];
[readwriteCharacteristic setDescriptors:@[readwriteCharacteristicDescription1]];
/*
只读的Characteristic
properties：CBCharacteristicPropertyRead
permissions CBAttributePermissionsReadable
*/
CBMutableCharacteristic *readCharacteristic = [[CBMutableCharacteristic alloc]initWithType:[CBUUID UUIDWithString:readCharacteristicUUID] properties:CBCharacteristicPropertyRead value:nil permissions:CBAttributePermissionsReadable];
//service1初始化并加入两个characteristics
CBMutableService *service1 = [[CBMutableService alloc]initWithType:[CBUUID UUIDWithString:ServiceUUID1] primary:YES];
NSLog(@"%@",service1.UUID);
[service1 setCharacteristics:@[notiyCharacteristic,readwriteCharacteristic]];
//service2初始化并加入一个characteristics
CBMutableService *service2 = [[CBMutableService alloc]initWithType:[CBUUID UUIDWithString:ServiceUUID2] primary:YES];
[service2 setCharacteristics:@[readCharacteristic]];
//添加后就会调用代理的- (void)peripheralManager:(CBPeripheralManager *)peripheral didAddService:(CBService *)service error:(NSError *)error
[peripheralManager addService:service1];
[peripheralManager addService:service2];
}
3.开启广播advertising
//perihpheral添加了service
- (void)peripheralManager:(CBPeripheralManager *)peripheral didAddService:(CBService *)service error:(NSError *)error{
if (error == nil) {
serviceNum++;
}
//因为我们添加了2个服务，所以想两次都添加完成后才去发送广播
if (serviceNum==2) {
//添加服务后可以在此向外界发出通告 调用完这个方法后会调用代理的
//(void)peripheralManagerDidStartAdvertising:(CBPeripheralManager *)peripheral error:(NSError *)error
[peripheralManager startAdvertising:@{
CBAdvertisementDataServiceUUIDsKey : @[[CBUUID UUIDWithString:ServiceUUID1],[CBUUID UUIDWithString:ServiceUUID2]],
CBAdvertisementDataLocalNameKey : LocalNameKey
}
];
}
}
//peripheral开始发送advertising
- (void)peripheralManagerDidStartAdvertising:(CBPeripheralManager *)peripheral error:(NSError *)error{
NSLog(@"in peripheralManagerDidStartAdvertisiong");
}
4.对central的操作进行响应
- 4.1 读characteristics请求
- 4.2 写characteristics请求
- 4.3 订阅和取消订阅characteristics
//订阅characteristics
-(void)peripheralManager:(CBPeripheralManager *)peripheral central:(CBCentral *)central didSubscribeToCharacteristic:(CBCharacteristic *)characteristic{
NSLog(@"订阅了 %@的数据",characteristic.UUID);
//每秒执行一次给主设备发送一个当前时间的秒数
timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(sendData:) userInfo:characteristic repeats:YES];
}
//取消订阅characteristics
-(void)peripheralManager:(CBPeripheralManager *)peripheral central:(CBCentral *)central didUnsubscribeFromCharacteristic:(CBCharacteristic *)characteristic{
NSLog(@"取消订阅 %@的数据",characteristic.UUID);
//取消回应
[timer invalidate];
}
//发送数据，发送当前时间的秒数
-(BOOL)sendData:(NSTimer *)t {
CBMutableCharacteristic *characteristic = t.userInfo;
NSDateFormatter *dft = [[NSDateFormatter alloc]init];
[dft setDateFormat:@"ss"];
NSLog(@"%@",[dft stringFromDate:[NSDate date]]);
//执行回应Central通知数据
return [peripheralManager updateValue:[[dft stringFromDate:[NSDate date]] dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:(CBMutableCharacteristic *)characteristic onSubscribedCentrals:nil];
}
//读characteristics请求
- (void)peripheralManager:(CBPeripheralManager *)peripheral didReceiveReadRequest:(CBATTRequest *)request{
NSLog(@"didReceiveReadRequest");
//判断是否有读数据的权限
if (request.characteristic.properties & CBCharacteristicPropertyRead) {
NSData *data = request.characteristic.value;
[request setValue:data];
//对请求作出成功响应
[peripheralManager respondToRequest:request withResult:CBATTErrorSuccess];
}else{
[peripheralManager respondToRequest:request withResult:CBATTErrorWriteNotPermitted];
}
}
//写characteristics请求
- (void)peripheralManager:(CBPeripheralManager *)peripheral didReceiveWriteRequests:(NSArray *)requests{
NSLog(@"didReceiveWriteRequests");
CBATTRequest *request = requests[0];
//判断是否有写数据的权限
if (request.characteristic.properties & CBCharacteristicPropertyWrite) {
//需要转换成CBMutableCharacteristic对象才能进行写值
CBMutableCharacteristic *c =(CBMutableCharacteristic *)request.characteristic;
c.value = request.value;
[peripheralManager respondToRequest:request withResult:CBATTErrorSuccess];
}else{
[peripheralManager respondToRequest:request withResult:CBATTErrorWriteNotPermitted];
}
}
项目中可以使用BabyBluetooth，这个The easiest way to use Bluetooth (BLE )in ios,even bady can use. 简单易用的蓝牙库，基于CoreBluetooth的封装，并兼容ios和mac osx.
为什么使用它？
1：基于原生CoreBluetooth框架封装的轻量级的开源库，可以帮你更简单地使用CoreBluetooth API。
2：CoreBluetooth所有方法都是通过委托完成，代码冗余且顺序凌乱。BabyBluetooth使用block方法，可以重新按照功能和顺序组织代码，并提供许多方法减少蓝牙开发过程中的代码量。
3:链式方法体，代码更简洁、优雅。
4:通过channel切换区分委托调用，并方便切换
5:便利的工具方法
6:完善的文档，且项目处于活跃状态，不断的更新中
7:github上star最多的纯Bluetooth类库
8:包含多种类型的demo和ios蓝牙开发教程
9:同时支持蓝牙设备中心模式和外设模式（central model and peripheral model）