ios11蓝牙有一些奇怪的东西

Question

当我在设置中关闭蓝牙时，我使用 CBCentralManager来获取这样的蓝牙状态：

self.bluetoothManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];

系统将显示这样的警报：系统警报

蓝牙的当前状态为 CBManagerStatePoweredOff。但是，当我在控制中心关闭蓝牙时，即使当前蓝牙状态仍然是CBManagerStatePoweredOff，此警报也不再显示。

在这种情况下，我如何提醒用户打开蓝牙？

Answer 1

您可以通过实现以下委托方法来提醒用户。

//Bluetooth state delegation
#pragma mark - CBCentralManagerDelegate
- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
    NSString *stateString = nil;
    switch(self.CBManager.state)
    {
        case CBManagerStateResetting:
        stateString = @"The connection with the system service was momentarily lost, update imminent.";
        break;
        case CBManagerStateUnsupported:
        stateString = @"The platform doesn't support Bluetooth Low Energy."; break;
        case CBManagerStateUnauthorized: stateString = @"The app is not authorized to use Bluetooth Low Energy.";
        break;
        case CBManagerStatePoweredOff:
        stateString = @"Bluetooth is currently powered off.";
        break;
        case CBManagerStatePoweredOn:
        [self.beaconManager startMonitoringForRegion:self.museumsRegion];
        [self.beaconManager startRangingBeaconsInRegion: self.museumsRegion];
        break;
        case CBManagerStateUnknown:
        stateString = @"State unknown, update imminent.";
        break;
    }
    NSLog(@"%@", stateString);
}

现在应自动通知用户。

Answer 2

您可以使用 cbcentralmanageroptionshowpoweraltkey 在选项中禁用系统蓝牙警报。

NSDictionary *options = @{CBCentralManagerOptionShowPowerAlertKey: @NO};
self.bluetoothManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil options:options];

然后，您可以使用Deleget方法 CentralManagerDidupDateState：弹出您自定义警报。