Question

iOS开发中如何实现app作为外设被连接的功能

Answer 1

在iOS应用开发中，蓝牙开发是一个重点， 是iOS开发人员必须掌握的一个知识。今天小编就将为大家分享一篇iOS大牛写的有关蓝牙开发中，使用app发布一个peripheral，给其他的central连接的实现方法。

上面这张图是什么意思呢，相信开发过蓝牙项目的童鞋应该都清楚，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

准备开发环境

1 、Xcode

2、 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，但是方法很负责，本篇分享不做过多赘述），如果不行可以使用osx程序调试

3、 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 = [[CBPeripheralManageralloc]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:[NSStringstringWithFormat:@"设备名%@已经打开，可以使用center进行连接",LocalNameKey]];
[self setUp];
break;
caseCBPeripheralManagerStatePoweredOff:
NSLog(@"powered off");
[info setText:@"poweredoff"];
break;
default:
break;
}
}
//配置bluetooch的
-(void)setUp{
//characteristics字段描述
CBUUID*CBUUIDCharacteristicUserDescriptionStringUUID = [CBUUIDUUIDWithString:CBUUIDCharacteristicUserDescriptionString];
/*
可以通知的Characteristic
properties：CBCharacteristicPropertyNotify
permissions CBAttributePermissionsReadable
*/
CBMutableCharacteristic*notiyCharacteristic = [[CBMutableCharacteristic alloc]initWithType:[CBUUIDUUIDWithString:notiyCharacteristicUUID]properties:CBCharacteristicPropertyNotify value:nilpermissions:CBAttributePermissionsReadable];
/*
可读写的characteristics
properties：CBCharacteristicPropertyWrite |CBCharacteristicPropertyRead
permissionsCBAttributePermissionsReadable | CBAttributePermissionsWriteable
*/
CBMutableCharacteristic*readwriteCharacteristic = [[CBMutableCharacteristic alloc]initWithType:[CBUUIDUUIDWithString:readwriteCharacteristicUUID]properties:CBCharacteristicPropertyWrite | CBCharacteristicPropertyReadvalue:nil permissions:CBAttributePermissionsReadable |CBAttributePermissionsWriteable];
//设置description
CBMutableDescriptor*readwriteCharacteristicDescription1 = [[CBMutableDescriptoralloc]initWithType: CBUUIDCharacteristicUserDescriptionStringUUID value:@"name"];
[readwriteCharacteristicsetDescriptors:@[readwriteCharacteristicDescription1]];
/*
只读的Characteristic
properties：CBCharacteristicPropertyRead
permissionsCBAttributePermissionsReadable
*/
CBMutableCharacteristic *readCharacteristic= [[CBMutableCharacteristic alloc]initWithType:[CBUUIDUUIDWithString:readCharacteristicUUID] properties:CBCharacteristicPropertyReadvalue:nil permissions:CBAttributePermissionsReadable];
//service1初始化并加入两个characteristics
CBMutableService *service1 =[[CBMutableService alloc]initWithType:[CBUUID UUIDWithString:ServiceUUID1]primary:YES];
[service1setCharacteristics:@[notiyCharacteristic,readwriteCharacteristic]];
//service2初始化并加入一个characteristics
CBMutableService *service2 =[[CBMutableService alloc]initWithType:[CBUUID UUIDWithString:ServiceUUID2]primary:YES];
[service2setCharacteristics:@[readCharacteristic]];
//添加后就会调用代理的- (void)peripheralManager:(CBPeripheralManager *)peripheraldidAddService:(CBService *)service error:(NSError *)error
[peripheralManageraddService:service1];
[peripheralManageraddService:service2];
}

3. 开启广播advertising
//perihpheral添加了service
-(void)peripheralManager:(CBPeripheralManager *)peripheraldidAddService:(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 : @[[CBUUIDUUIDWithString:ServiceUUID1],[CBUUID UUIDWithString:ServiceUUID2]],
CBAdvertisementDataLocalNameKey : LocalNameKey
}
];
}
}
//peripheral开始发送advertising
-(void)peripheralManagerDidStartAdvertising:(CBPeripheralManager *)peripheralerror:(NSError *)error{
NSLog(@"inperipheralManagerDidStartAdvertisiong");
}

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 *)centraldidSubscribeToCharacteristic:(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:1target:self selector:@selector(sendData:) userInfo:characteristic repeats:YES];
}
//取消订阅characteristics
-(void)peripheralManager:(CBPeripheralManager*)peripheral central:(CBCentral *)centraldidUnsubscribeFromCharacteristic:(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 = [[NSDateFormatteralloc]init];
[dft setDateFormat:@"ss"];
NSLog(@"%@",[dftstringFromDate:[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 *)peripheraldidReceiveReadRequest:(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
[peripheralManagerrespondToRequest:request withResult:CBATTErrorSuccess];
}else{
[peripheralManagerrespondToRequest:request withResult:CBATTErrorWriteNotPermitted];
}
}
//写characteristics请求
-(void)peripheralManager:(CBPeripheralManager *)peripheraldidReceiveWriteRequests:(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;
[peripheralManagerrespondToRequest:request withResult:CBATTErrorSuccess];
}else{
[peripheralManagerrespondToRequest:request withResult:CBATTErrorWriteNotPermitted];
}
}

以上就是iOS蓝牙开发中，app作为外设被连接的具体实现方法，希望对大家开发这项功能有所帮助吧。