發佈MKReverseGeocoder會導致我的應用崩潰！

Question

我需要知道我的用戶來自哪裏，所以我做了一個單獨的對象，它獲取座標並使用mapkit獲取我需要的國家代碼。

這是我的頭文件：

#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 

和實現：

#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，調用stopGeoCoder方法讓我的應用程序崩潰，甚至通過performSelectorOnMainThread調用它...

的問題在於以下幾行：

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

當我試圖釋放它時，似乎MKReverseGeocoder變得非常生氣！ 我只在「didFail」方法中發生崩潰。 實際上，當它發現地標時，另一個類將得到通知，執行某些操作並調用stopGeocoder，並且它不會崩潰！ WTF？

Answer 1

你應該參考另一篇文章中的堆棧溢出與解決方案：

cllocation and mkreversegeocoder