iOS11藍牙有些奇怪

Question

當我關閉藍牙設置時，我使用CBCentralManager來獲取藍牙狀態，如下所示：

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

系統將顯示如下警報： system alert

藍牙的當前狀態為CBManagerStatePoweredOff 。 但是，當我在控制中心中關閉Bluetooth時，即使Bluetooth的當前狀態仍為CBManagerStatePoweredOff ，也不再顯示此警報。

在這種情況下，我如何提醒用戶打開藍牙？

Answer 1

您可以通過實現以下委托方法來提醒用戶。

//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);
}

現在應該自動通知用戶。

Answer 2

您可以通過在選項dict中使用CBCentralManagerOptionShowPowerAlertKey來禁用系統藍牙警報。

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：彈出自定義警報。