iOS检测蓝牙是否开启

首先在build phase中添加CoreBluetooth.framework
然后在你的.m文件中#import <CoreBluetooth/CoreBluetooth.h>
初始化

• (CBCentralManager *)bluetoothManager {
  if (_bluetoothManager == nil) {
  _bluetoothManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
  }
  return _bluetoothManager;
  }

实现代理方法

• (void)centralManagerDidUpdateState:(CBCentralManager *)central {
  UIView *mainView = [[UIApplication sharedApplication].windows firstObject];

  switch (central.state) {
  case CBCentralManagerStatePoweredOff:{
  [mainView makeToast:@"蓝牙没有开启，在设置中打开蓝牙"];
  }
  break;
  case CBCentralManagerStatePoweredOn:
  break;
  case CBCentralManagerStateResetting:
  break;
  case CBCentralManagerStateUnauthorized:
  break;
  case CBCentralManagerStateUnknown:
  break;
  case CBCentralManagerStateUnsupported:
  [mainView makeToast:@"当前设备不支持蓝牙"];
  break;
  default:
  break;
  }
  }
  通过这个代理方法就可以得到当前设备的蓝牙状态了