ios蓝牙开发（三）ios连接外设的代码实现：手机app去读写蓝牙设备。

手机app去读写蓝牙设备。。。。。。。

代码下载:

原文博客主提供Github代码连接，地址是：https://github.com/coolnameismy/demo

ios连接外设的代码实现流程：

1. 建立中心角色

2. 扫描外设（discover）

3. 连接外设(connect)

4. 扫描外设中的服务和特征(discover)

- 4.1 获取外设的services

- 4.2 获取外设的Characteristics,获取Characteristics的值，获取Characteristics的Descriptor和Descriptor的值

5. 与外设做数据交互(explore and interact)

6. 订阅Characteristic的通知

7. 断开连接(disconnect)

准备环境

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，但是方法很蛋疼，我会放在最后说）

3 蓝牙外设

实现步骤

1 导入CoreBluetooth头文件，建立主设备管理类，设置主设备委托

#import <CoreBluetooth/CoreBluetooth.h>

@interface ViewController : UIViewController<CBCentralManagerDelegate>

@interface ViewController (){

//系统蓝牙设备管理对象，可以把他理解为主设备，通过他，可以去扫描和链接外设

CBCentralManager *manager;

//用于保存被发现设备

NSMutableArray *peripherals;

}

- (void)viewDidLoad {

[super viewDidLoad];

/*

设置主设备的委托,CBCentralManagerDelegate

必须实现的：

- (void)centralManagerDidUpdateState:(CBCentralManager *)central;//主设备状态改变的委托，在初始化CBCentralManager的适合会打开设备，只有当设备正确打开后才能使用

其他选择实现的委托中比较重要的：

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI; //找到外设的委托

- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//连接外设成功的委托

- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外设连接失败的委托

- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//断开外设的委托

*/

//初始化并设置委托和线程队列，最好一个线程的参数可以为nil，默认会就main线程

manager = [[CBCentralManager alloc]initWithDelegate:self queue:dispatch_get_main_queue()];

2 扫描外设（discover），扫描外设的方法我们放在centralManager成功打开的委托中，因为只有设备成功打开，才能开始扫描，否则会报错。

-(void)centralManagerDidUpdateState:(CBCentralManager *)central{

switch (central.state) {

case CBCentralManagerStateUnknown:

NSLog(@">>>CBCentralManagerStateUnknown");

break;

case CBCentralManagerStateResetting:

NSLog(@">>>CBCentralManagerStateResetting");

break;

case CBCentralManagerStateUnsupported:

NSLog(@">>>CBCentralManagerStateUnsupported");

break;

case CBCentralManagerStateUnauthorized:

NSLog(@">>>CBCentralManagerStateUnauthorized");

break;

case CBCentralManagerStatePoweredOff:

NSLog(@">>>CBCentralManagerStatePoweredOff");

break;

case CBCentralManagerStatePoweredOn:

NSLog(@">>>CBCentralManagerStatePoweredOn");

//开始扫描周围的外设

/*

第一个参数nil就是扫描周围所有的外设，扫描到外设后会进入

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;

*/

[manager scanForPeripheralsWithServices:nil options:nil];

break;

default:

break;

}

}

//扫描到设备会进入方法

-(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{

NSLog(@"当扫描到设备:%@",peripheral.name);

//接下来可以连接设备

}

3 连接外设(connect)

//扫描到设备会进入方法

-(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{

//接下连接我们的测试设备，如果你没有设备，可以下载一个app叫lightbule的app去模拟一个设备

//这里自己去设置下连接规则，我设置的是P开头的设备

if ([peripheral.name hasPrefix:@"P"]){

/*

一个主设备最多能连7个外设，每个外设最多只能给一个主设备连接,连接成功，失败，断开会进入各自的委托

- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//连接外设成功的委托

- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外设连接失败的委托

- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//断开外设的委托

*/

//找到的设备必须持有它，否则CBCentralManager中也不会保存peripheral，那么CBPeripheralDelegate中的方法也不会被调用！！

[peripherals addObject:peripheral];

//连接设备

[manager connectPeripheral:peripheral options:nil];

}

}

//连接到Peripherals-成功

- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral

{

NSLog(@">>>连接到名称为（%@）的设备-成功",peripheral.name);

}

//连接到Peripherals-失败

-(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error

{

NSLog(@">>>连接到名称为（%@）的设备-失败,原因:%@",[peripheral name],[error localizedDescription]);

}

//Peripherals断开连接

- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{

NSLog(@">>>外设连接断开连接 %@: %@\n", [peripheral name], [error localizedDescription]);

}

4扫描外设中的服务和特征(discover)

设备连接成功后，就可以扫描设备的服务了，同样是通过委托形式，扫描到结果后会进入委托方法。但是这个委托已经不再是主设备的委托（CBCentralManagerDelegate），而是外设的委托（CBPeripheralDelegate）,这个委托包含了主设备与外设交互的许多 回叫方法，包括获取services，获取characteristics，获取characteristics的值，获取characteristics的Descriptor，和Descriptor的值，写数据，读rssi，用通知的方式订阅数据等等。

4.1获取外设的services

//连接到Peripherals-成功

- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral

{

NSLog(@">>>连接到名称为（%@）的设备-成功",peripheral.name);

//设置的peripheral委托CBPeripheralDelegate

//@interface ViewController : UIViewController<CBCentralManagerDelegate,CBPeripheralDelegate>

[peripheral setDelegate:self];

//扫描外设Services，成功后会进入方法：-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{

[peripheral discoverServices:nil];

}

//扫描到Services

-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{

//  NSLog(@">>>扫描到服务：%@",peripheral.services);

if (error)

{

NSLog(@">>>Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]);

return;

}

for (CBService *service in peripheral.services) {

NSLog(@"%@",service.UUID);

//扫描每个service的Characteristics，扫描到后会进入方法： -(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error

[peripheral discoverCharacteristics:nil forService:service];

}

}

### 4.2获取外设的Characteristics,获取Characteristics的值，获取Characteristics的Descriptor和Descriptor的值

//扫描到Characteristics

-(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error{

if (error)

{

NSLog(@"error Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]);

return;

}

for (CBCharacteristic *characteristic in service.characteristics)

{

NSLog(@"service:%@ 的 Characteristic: %@",service.UUID,characteristic.UUID);

}

//获取Characteristic的值，读到数据会进入方法：-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error

for (CBCharacteristic *characteristic in service.characteristics){

{

[peripheral readValueForCharacteristic:characteristic];

}

}

//搜索Characteristic的Descriptors，读到数据会进入方法：-(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error

for (CBCharacteristic *characteristic in service.characteristics){

[peripheral discoverDescriptorsForCharacteristic:characteristic];

}

}

//获取的charateristic的值

-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{

//打印出characteristic的UUID和值

//!注意，value的类型是NSData，具体开发时，会根据外设协议制定的方式去解析数据

NSLog(@"characteristic uuid:%@  value:%@",characteristic.UUID,characteristic.value);

}

//搜索到Characteristic的Descriptors

-(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{

//打印出Characteristic和他的Descriptors

NSLog(@"characteristic uuid:%@",characteristic.UUID);

for (CBDescriptor *d in characteristic.descriptors) {

NSLog(@"Descriptor uuid:%@",d.UUID);

}

}

//获取到Descriptors的值

-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(CBDescriptor *)descriptor error:(NSError *)error{

//打印出DescriptorsUUID 和value

//这个descriptor都是对于characteristic的描述，一般都是字符串，所以这里我们转换成字符串去解析

NSLog(@"characteristic uuid:%@  value:%@",[NSString stringWithFormat:@"%@",descriptor.UUID],descriptor.value);

}

5 把数据写到Characteristic中

//写数据

-(void)writeCharacteristic:(CBPeripheral *)peripheral

characteristic:(CBCharacteristic *)characteristic

value:(NSData *)value{

//打印出 characteristic 的权限，可以看到有很多种，这是一个NS_OPTIONS，就是可以同时用于好几个值，常见的有read，write，notify，indicate，知知道这几个基本就够用了，前连个是读写权限，后两个都是通知，两种不同的通知方式。

/*

typedef NS_OPTIONS(NSUInteger, CBCharacteristicProperties) {

CBCharacteristicPropertyBroadcast = 0x01,

CBCharacteristicPropertyRead = 0x02,

CBCharacteristicPropertyWriteWithoutResponse = 0x04,

CBCharacteristicPropertyWrite = 0x08,

CBCharacteristicPropertyNotify = 0x10,

CBCharacteristicPropertyIndicate = 0x20,

CBCharacteristicPropertyAuthenticatedSignedWrites = 0x40,

CBCharacteristicPropertyExtendedProperties = 0x80,

CBCharacteristicPropertyNotifyEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0) = 0x100,

CBCharacteristicPropertyIndicateEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0) = 0x200

};

*/

NSLog(@"%lu", (unsigned long)characteristic.properties);

//只有 characteristic.properties 有write的权限才可以写

if(characteristic.properties & CBCharacteristicPropertyWrite){

/*

最好一个type参数可以为CBCharacteristicWriteWithResponse或type:CBCharacteristicWriteWithResponse,区别是是否会有反馈

*/

[peripheral writeValue:value forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse];

}else{

NSLog(@"该字段不可写！");

}

}

6 订阅Characteristic的通知

//设置通知

-(void)notifyCharacteristic:(CBPeripheral *)peripheral

characteristic:(CBCharacteristic *)characteristic{

//设置通知，数据通知会进入：didUpdateValueForCharacteristic方法

[peripheral setNotifyValue:YES forCharacteristic:characteristic];

}

//取消通知

-(void)cancelNotifyCharacteristic:(CBPeripheral *)peripheral

characteristic:(CBCharacteristic *)characteristic{

[peripheral setNotifyValue:NO forCharacteristic:characteristic];

}

7 断开连接(disconnect)

//停止扫描并断开连接

-(void)disconnectPeripheral:(CBCentralManager *)centralManager

peripheral:(CBPeripheral *)peripheral{

//停止扫描

[centralManager stopScan];

//断开连接

[centralManager cancelPeripheralConnection:peripheral];

}

代码下载:

博客中大部分示例代码都上传到了github，地址是：https://github.com/coolnameismy/demo