iOS11蓝牙有点奇怪

当我在设置中关闭蓝牙时，我使用 CBCentralManager 来获取蓝牙的状态，如下所示:

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

系统将显示如下警告:system alert

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

在这种情况下如何提醒用户开启蓝牙？

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Best Answer-推荐答案

您可以通过实现以下 delegate 方法来提醒用户。

//Bluetooth state delegation
#pragma mark - CBCentralManagerDelegate

- (void)centralManagerDidUpdateStateCBCentralManager *)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);
}

现在应该自动通知用户。

关于iOS11蓝牙有点奇怪，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46426163/