为什么信标会导致蓝牙不断切换？

Question

我在使用 iOS 和 iBeacon 时遇到了一个非常奇怪的错误。我有一个非常简单的 BeaconManager，它用特定的 UUID、主要和次要值来排列信标，并在找到它们后执行一些操作。我的应用程序似乎可以正常工作，直到它不断切换蓝牙状态并停止工作。唯一可见的结果是状态栏中的蓝牙图标由于蓝牙停止和重新启动而开始闪烁。

关注点在哪里？

这是我的class定义：

#import "BeaconManager.h"

@implementation BeaconManager

- (instancetype)init {
    self = [super init];
    if (self) {
        NSURL *beep = [[NSBundle mainBundle] URLForResource:@"beep" withExtension:@"aiff"];
        soundFileURLRef = (CFURLRef) CFBridgingRetain(beep);
        AudioServicesCreateSystemSoundID(soundFileURLRef, &soundFileObject);

        // Initializes properties
        beacon = [CLBeacon new];
        foundBeacons = [NSMutableArray new];
        _lastBeaconActionTimes = [[NSMutableDictionary alloc] init];
    }
    return self;
}

- (void)initRegion {
    // Initializes the beacon region by giving it an UUID and an identifier
    NSUUID *uuid = [[NSUUID alloc] initWithUUIDString:BEACON];
    beaconRegion = [[CLBeaconRegion alloc] initWithProximityUUID:uuid identifier:@"beacon.region"];
    // Starts looking for beacon within the region
    [self.locationManager startMonitoringForRegion:beaconRegion];
}

- (void)checkBeacon {
    if (!self.locationManager) {
        self.locationManager = [[CLLocationManager alloc] init];
        self.locationManager.delegate = self;

        if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)])
            [self.locationManager requestWhenInUseAuthorization];
    }
    [self initRegion];
    [self locationManager:self.locationManager didStartMonitoringForRegion:beaconRegion];
}

#pragma mark - CLLocationManagerDelegate

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
    [self.locationManager startMonitoringForRegion:beaconRegion];
    [self.locationManager startRangingBeaconsInRegion:beaconRegion];
}

- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region {
    [self.locationManager startRangingBeaconsInRegion:beaconRegion];
}

- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region {
    [self.locationManager stopRangingBeaconsInRegion:beaconRegion];
}

- (void)locationManager:(CLLocationManager *)manager monitoringDidFailForRegion:(CLRegion *)region withError:(NSError *)error {
    NSLog(@"Failed monitoring region: %@", error);
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    NSLog(@"Location manager failed: %@", error);
}

- (void)locationManager:(CLLocationManager *)manager
        didRangeBeacons:(NSArray *)beacons
               inRegion:(CLBeaconRegion *)region {

    if (foundBeacons.count == 0) {
        for (CLBeacon *filterBeacon in beacons) {
            // If a beacon is located near the device and its major value is equal to 1000 (MAJOR constant)
            if (((filterBeacon.proximity == CLProximityImmediate) || (filterBeacon.proximity == CLProximityNear)))
                // Registers the beacon to the list of found beacons
                [foundBeacons addObject:filterBeacon];
        }
    }
    // Did some beacon get found?
    if (foundBeacons.count > 0) {
        // Takes first beacon of the list
        beacon = [foundBeacons firstObject];

        if (([beacon.major isEqualToNumber:[NSNumber numberWithInt:MAJOR]]) && ([beacon.minor isEqualToNumber:[NSNumber numberWithInt:MINOR]])) {
            // Takes the actual date and time
            NSDate *now = [[NSDate alloc] init];
            NSString *key = [NSString stringWithFormat:@"%@ %@ %@", [beacon.proximityUUID UUIDString], beacon.major, beacon.minor];
            NSDate *lastBeaconActionTime = [_lastBeaconActionTimes objectForKey:key];
            if ((lastBeaconActionTime == nil) || ([now timeIntervalSinceDate:lastBeaconActionTime] > MINIMUM_ACTION_INTERVAL_SECONDS)) {
                [_lastBeaconActionTimes setObject:now forKey:key];
                // Plays beep sound
                AudioServicesPlaySystemSound(soundFileObject);

                if (self.delegate) {
                    // Performs actions related to the beacon (i.e. delivers a coupon)
                    [self.delegate didFoundBeacon:self];
                }
                self.locationManager = nil;
            }
            // else [self.locationManager stopMonitoringForRegion:region];
        }
        [foundBeacons removeObjectAtIndex:0];
        beacon = nil;
    }
}
@end

Answer 1

不能肯定这就是蓝牙不断切换的原因，但这部分肯定是可疑的：

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
    [self.locationManager startMonitoringForRegion:beaconRegion];
    [self.locationManager startRangingBeaconsInRegion:beaconRegion];
}

这本质上是一个无限循环。监控开始后，iOS 调用 didStartMonitoring 方法……它开始监控同一区域，这使得 iOS 再次调用 didStartMonitoring 方法，这……

我将从您的这部分代码中删除 startMonitoringForRegion 行开始。

为什么信标会导致蓝牙不断切换？

Why beacons cause Bluetooth to continuously toggle?

bluetooth

ios

ibeacon