iOS蓝牙开发（三）：App作为外设被连接的实现

本文主要是介绍iOS蓝牙开发（三）：App作为外设被连接的实现，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

http://www.cocoachina.com/ios/20160218/15299.html

在上一节说了app作为central连接peripheral的情况，这一节介绍如何使用app发布一个peripheral，给其他的central连接。

还是这张图，central模式用的都是左边的类，而peripheral模式用的是右边的类

peripheral模式的流程

1. 打开peripheralManager，设置peripheralManager的委托

2. 创建characteristics，characteristics的description 创建service，把characteristics添加到service中，再把service添加到peripheralManager中

3. 开启广播advertising

4. 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

##准备环境

Xcode
开发证书和手机（蓝牙程序需要使用使用真机调试，使用模拟器也可以调试，但是方法很蛋疼，我会放在最后说），如果不行可以使用osx程序调试
蓝牙外设

##实现步骤

1.打开peripheralManager，设置peripheralManager的委托

设置当前ViewController实现CBPeripheralManagerDelegate委托

  @interface BePeripheralViewController : UIViewController 
 

初始化peripheralManager

  /* 
 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characteristics，characteristics的description ，创建service，把characteristics添加到service中，再把service添加到peripheralManager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。

  //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 ; 
      } 
 } 
 

  //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]; 
          [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]; 
      } 
 } 
 