过去几天我一直在想这个问题，它开始慢慢地耗尽我的精力。我正在尝试制作 CLLocationManager Singleton，因为我需要应用程序的其他两个组件的位置。但是，当我设置 currentLocation 属性时，我不断收到 EXC_BAD_ACCESS 。当我通过它时，我在 main.m 上收到一个 SIGABRT 哦，最重要的是，什么时候通过，以及 SIGABRT 我被告知我的 KVO 消息已收到但未处理，我不知道是什么这意味着。
任何帮助以及有关 KVO 的资源和/或我在使用 KVO 之前应该了解的基础知识的资源，我们将不胜感激
LocationFetch.h
@interface LocationFetch : NSObject <CLLocationManagerDelegate>
+(LocationFetch *) sharedInstance;
@property (nonatomic,strong) CLLocationManager *locationManager;
@property (nonatomic, strong) CLLocation *currentLocation;
-(void)startingUpdatingLocation;
-(void)stopUpdatingLocation;
@end
LocationFetch.m
#import "LocationFetch.h"
@implementation LocationFetch
@synthesize locationManager, currentLocation;
+(LocationFetch *) sharedInstance
{
static LocationFetch *instance;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
instance = [[self alloc]init];
});
return instance;
}
- (id)init
{
self = [super init];
if(self)
{
self.locationManager = [[CLLocationManager alloc]init];
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
self.locationManager.distanceFilter = 100;
self.locationManager.delegate = self;
//Request Authorization
if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)])
{
[self.locationManager requestWhenInUseAuthorization];
}
}
return self;
}
- (void)startingUpdatingLocation
{
[self.locationManager startUpdatingLocation];
NSLog(@"Starting Location Updates");
}
-(void)stopUpdatingLocation
{
[self.locationManager stopUpdatingLocation];
NSLog(@"Stopping Location Updates");
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSLog(@"Location updates failed with %@", error);
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray<CLLocation *> *)locations
{
CLLocation *location = [locations lastObject];
NSLog(@"LocationFetch sharedInstance: Latitude %+.6f, Longitude %+.6f\n",
location.coordinate.latitude,
location.coordinate.longitude);
self.currentLocation = location;
}
@end
WeatherFetch.m 的一部分(这是观察者注册的地方)
-(id)init
{
self = [super init];
if(self)
{
[[LocationFetch sharedInstance] addObserver:self forKeyPath:@"currentLocation" options:NSKeyValueObservingOptionNew context:nil];
}
return self;
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object
change:(NSDictionary *)change context:(void *)context
{
if([keyPath isEqualToString:@"currentLocation"]) {
[self setWeatherLocation];
[self sendWeatherRequest];
NSLog(@"Observer has received message");
[self removeObserver:self forKeyPath:@"currentLocation" context:nil];
}
}
编辑:这是我遵循的单例指南:http://derpturkey.com/cllocationmanager-singleton/
另一个编辑:好的，我通过删除 CLLocationManager 和 CLLocation 的强属性和非原子属性解决了 EXC_BAD_ACCESS 错误，但现在 SIGABRT 是一个更关键的问题，这是异常的调试输出。好的一面是，KVO 现在似乎已收到通知，只是不明白错误“消息已收到但未处理”
2016-06-24 21:25:51.111 TrafficAlarmClock[1504:18554] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '(
"<CALayer: 0x7f95a043eb00>"
): An -observeValueForKeyPath:ofObject:change:context: message was received but not handled.
Key path: currentLocation
Observed object: <LocationFetch: 0x7f95a040c5a0>
Change: {
kind = 1;
new = "<+40.75921100,-73.98463800> +/- 5.00m (speed -1.00 mps / course -1.00) @ 6/24/16, 9:25:50 PM Eastern Daylight Time";
}
Context: 0x1050f7c08'
*** First throw call stack:
(
0 CoreFoundation 0x0000000105f97d85 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000105682deb objc_exception_throw + 48
2 CoreFoundation 0x0000000105f97cbd +[NSException raise:format:] + 205
3 Foundation 0x00000001052e71ae -[NSObject(NSKeyValueObserving) observeValueForKeyPath:ofObject:change:context:] + 168
4 Foundation 0x0000000105213cad NSKeyValueNotifyObserver + 347
5 Foundation 0x0000000105212f39 NSKeyValueDidChange + 466
6 Foundation 0x00000001052e7fff -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:usingBlock:] + 912
7 Foundation 0x0000000105210804 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKey:key:key:usingBlock:] + 60
8 Foundation 0x000000010526ea9b _NSSetObjectValueAndNotify + 261
9 TrafficAlarmClock 0x00000001050f2143 -[LocationFetch locationManager:didUpdateLocations:] + 227
10 CoreLocation 0x0000000105192418 CLClientGetCapabilities + 20974
11 CoreLocation 0x000000010518e823 CLClientGetCapabilities + 5625
12 CoreLocation 0x00000001051892dd CLClientInvalidate + 923
13 CoreFoundation 0x0000000105ebd2ec __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
14 CoreFoundation 0x0000000105eb2f75 __CFRunLoopDoBlocks + 341
15 CoreFoundation 0x0000000105eb2d28 __CFRunLoopRun + 2472
16 CoreFoundation 0x0000000105eb20f8 CFRunLoopRunSpecific + 488
17 GraphicsServices 0x0000000108660ad2 GSEventRunModal + 161
18 UIKit 0x000000010634ef09 UIApplicationMain + 171
19 TrafficAlarmClock 0x00000001050f1b6f main + 111
20 libdyld.dylib 0x0000000108fd192d start + 1
21 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
另一个编辑:好的，我想我完全不明白将观察者之类的东西放置到我的应用程序中的哪里。我现在有了它，这样我的 View Controller 就是订阅者，现在我越来越接近我想要的行为。如果有人对 MVC 和 MVC/iOS 开发的软件设计有好的指南，请分享。也欢迎推荐书籍。
最佳答案
无法说出导致 KVO 错误的原因，因为缺乏精度，但只是告诉我们在类似情况下做了什么
这就是我们分配 LocationHelper 实例的方式:
- (id)init { self = [super init];
if (!self) {
return self;
}
// Check if the service is available
if ([CLLocationManager locationServicesEnabled])
{
// Init the location manager
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
self.locationManager.pausesLocationUpdatesAutomatically = YES;
self.locationManager.desiredAccuracy = LOCATION_ACCURACY_IN_METER;
}
return self;}
然后我不明白你为什么不使用:
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
然后使用 manager.location 从此处调用 setWeatherLocation 或 sendWeatherRequest。
如果这不是您所期望的，请提供有关崩溃的更多详细信息
关于ios - 设置属性导致 EXC_BAD_ACCESS 崩溃(CLLocationManager Singleton)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38023074/