蓝牙

监控蓝牙的状态：

1.引入#import <CoreBluetooth/CoreBluetooth.h>蓝牙框架

2.遵循其代理 CBPeripheralManagerDelegate

3.创建蓝牙对象 CBPeripheralManager *manager = [[CBPeripheralManager alloc] initWithDelegate:self queue:nil];

4.实现其代理事件

-(void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral{

 　　 switch (peripheral.state) {

        case CBCentralManagerStateUnknown:

            NSLog(@"未知状态");

            break;

        case CBCentralManagerStateResetting:

            NSLog(@"正在重置");

            break;

        case CBCentralManagerStateUnsupported:

            NSLog(@"不支持蓝牙设备");

            break;

        case CBCentralManagerStateUnauthorized:

            NSLog(@"未授权");

            break;

        case CBPeripheralManagerStatePoweredOn:

            NSLog(@"蓝牙打开");

            break;

        case CBPeripheralManagerStatePoweredOff:

            NSLog(@"蓝牙关闭");

            break;

        default:

            break;

    }

 }