背景：

1.iOS的蓝牙不能用来传输文件。

2.iOS与iOS设备之间进行数据通信，使用gameKit.framework

3.iOS与其他非iOS设备进行数据通信，使用coreBluetooth.framework

iOS中蓝牙的实现方案

iOS中提供了4个框架用于实现蓝牙连接

GameKit.framework（用法简单）

只能用于iOS设备之间的连接，多用于游戏（比如五子棋对战），从iOS7开始过期

MultipeerConnectivity.framework

只能用于iOS设备之间的连接，从iOS7开始引入，主要用于文件共享（仅限于沙盒的文件）

ExternalAccessory.framework

可用于第三方蓝牙设备交互，但是蓝牙设备必须经过苹果MFi认证（国内较少）

CoreBluetooth.framework（时下热门）

可用于第三方蓝牙设备交互，必须要支持蓝牙4.0

硬件至少是4s，系统至少是iOS6

蓝牙4.0以低功耗著称，一般也叫BLE（BluetoothLowEnergy）

目前应用比较多的案例：运动手坏、嵌入式设备、智能家居

下面具体介绍使用CoreBluetooth.framework的代码步骤：

//蓝牙系统库#import 
    
     //必须要由UUID来唯一标示对应的service和characteristic#define kServiceUUID @"5C476471-1109-4EBE-A826-45B4F9D74FB9" #define kCharacteristicHeartRateUUID @"82C7AC0F-6113-4EC9-92D1-5EEF44571398" #define kCharacteristicBodyLocationUUID @"537B5FD6-1889-4041-9C35-F6949D1CA034" @interface ViewController ()
     
       @property (nonatomic,strong)CBCentralManager * centralManager; @property (nonatomic,strong)CBPeripheral * peripheral; @end
     
    

1.创建中心角色

#import 
    
      - (void)viewDidLoad{    [super viewDidLoad];    //初始化蓝牙 central manager _centralManager = [[CBCentralManager alloc]initWithDelegate:self queue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0) options:nil]; }
    

2.扫描外设

[manager scanForPeripheralsWithServices:nil options:@{CBCentralManagerRestoredStateScanOptionsKey:@(YES)}];

3.连接外设

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI {        if([peripheral.name isEqualToString:BLE_SERVICE_NAME]){ [self connect:peripheral]; } s); } -(BOOL)connect:(CBPeripheral *)peripheral{ self.manager.delegate = self; [self.manager connectPeripheral:peripheral options:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:CBConnectPeripheralOptionNotifyOnDisconnectionKey]]; }

4.扫描外设中的服务和特征

- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {     NSLog(@"Did connect to peripheral: %@", peripheral);     _testPeripheral = peripheral;     [peripheral setDelegate:self];  
//查找服务 [peripheral discoverServices:nil]; }

发现服务：

- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error {     NSLog(@"didDiscoverServices");     if (error) { NSLog(@"Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]); if ([self.delegate respondsToSelector:@selector(DidNotifyFailConnectService:withPeripheral:error:)]) [self.delegate DidNotifyFailConnectService:nil withPeripheral:nil error:nil]; return; } for (CBService *service in peripheral.services) { //发现服务 if ([service.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_PROPRIETARY_SERVICE]]) { NSLog(@"Service found with UUID: %@", service.UUID); 
//查找特征 [peripheral discoverCharacteristics:nil forService:service]; break; } } }

发现服务中的特征：

- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error{    if (error)    {        NSLog(@"Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]); [self error]; return; } NSLog(@"服务：%@",service.UUID); for (CBCharacteristic *characteristic in service.characteristics) { //发现特征 if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:@"xxxxxxx"]]) { NSLog(@"监听：%@",characteristic);
//监听特征 [self.peripheral setNotifyValue:YES forCharacteristic:characteristic]; } } }

5.与外设进行数据交互

读取数据：

- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{    if (error)    {        NSLog(@"Error updating value for characteristic %@ error: %@", characteristic.UUID, [error localizedDescription]); self.error_b = BluetoothError_System; [self error]; return; } // NSLog(@"收到的数据：%@",characteristic.value); [self decodeData:characteristic.value]; }

写数据：

NSData *d2 = [[PBABluetoothDecode sharedManager] HexStringToNSData:@"0x02"];                [self.peripheral writeValue:d2 forCharacteristic:characteristic type:CBChar