发布 MK 反向地理编码器使我的应用程序崩溃！

Posted 2023-03-06

【中文标题】发布 MK 反向地理编码器使我的应用程序崩溃！

【英文标题】：Releasing MKReverseGeocoder makes my app crash!

【发布时间】：2011-04-18 15:32:44

【问题描述】：

我需要知道我的用户来自哪里，所以我制作了一个小单例对象，它获取坐标并使用 mapkit 获取我需要的国家代码。

这是我的头文件：

#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>

#define TW_GEO_CODER_CHANGED_STATE  @"TW_GEO_CODER_CHANGED_STATE"

@interface TWGeoCoder : NSObject <CLLocationManagerDelegate, MKReverseGeocoderDelegate>

    CLLocationManager *locationManager;
    MKReverseGeocoder *geoCoder;

    NSString *currentCountryIsoCode;


+ (TWGeoCoder*) sharedTWGeoCoder;

-(void) startGeoCoder;
-(void) stopGeoCoder;


@property (nonatomic, retain) NSString *currentCountryIsoCode;

@end

以及实现：

#import "TWGeoCoder.h"

@implementation TWGeoCoder


static TWGeoCoder* _singleton;

+ (TWGeoCoder*) sharedTWGeoCoder

    @synchronized([TWGeoCoder class])
    
        if (_singleton == nil)
        
            _singleton = [[TWGeoCoder alloc] init];
        
    
    return _singleton;



- (void)startGeoCoder
  
    if (locationManager == nil) 
    
        locationManager = [[CLLocationManager alloc] init];
    
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
    locationManager.distanceFilter = kCLDistanceFilterNone;
    locationManager.purpose = NSLocalizedString(@"#LocalizationPurpose",nil);
    [locationManager startUpdatingLocation];


- (void) stopGeoCoder 
            
    if (geoCoder != nil)
    
        [geoCoder cancel];
        [geoCoder release];
        geoCoder = nil;
    

    if (locationManager != nil)
    
        [locationManager stopUpdatingLocation];
        [locationManager release];
        locationManager = nil;
    



#pragma mark -
#pragma mark locationManager Delegate 

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 

    if (geoCoder == nil)
    
        geoCoder = [[MKReverseGeocoder alloc] initWithCoordinate:newLocation.coordinate];
    

    geoCoder.delegate = self;
    [geoCoder start];       



- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error 

    NSLog(@"locationManager:%@ didFailWithError:%@", manager, error);
    [self stopGeoCoder];




#pragma mark -
#pragma mark reverseGeocoder Delegate 

- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark


    self.currentCountryIsoCode = placemark.countryCode;

    [[NSNotificationCenter defaultCenter] postNotificationName:TW_GEO_CODER_CHANGED_STATE 
                                                        object:self];



- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFailWithError:(NSError *)error

    NSLog(@"reverseGeocoder:%@ didFailWithError:%@", geocoder, error);
    [self stopGeoCoder];    



#pragma mark -
#pragma mark Synthesizes

@synthesize currentCountryIsoCode;

@end

好吧，调用 stopGeoCoder 方法会使我的应用崩溃，甚至通过 performSelectorOnMainThread 调用它...

问题出在以下几行：

if (geoCoder != nil)
    
        [geoCoder cancel];
        [geoCoder release];
        geoCoder = nil;
    

MKReverseGeocoder 似乎在我尝试释放它时变得非常生气！ 我只在“didFail”方法上发生崩溃。 实际上，当它找到地标时，另一个类会收到通知，执行某些操作并调用 stopGeocoder 并且......它不会崩溃！ 什么鬼？

【参考方案1】：

你应该参考另一篇关于堆栈溢出的帖子的解决方案：

cllocation and mkreversegeocoder