MKAnnotations沒有被添加到mapview

由於某些原因，下面的代碼沒有添加註釋到地圖視圖。當我註銷一個計數時，它返回0，儘管它經歷了數組近50次。 Attraction對象實現MKAnnotation協議。MKAnnotations沒有被添加到mapview

-(void)forwardGeocoderFoundLocation 
{ 
int searchResults = [attractions count]; 
for(int i = 0; i < searchResults; i++){ 
    Attraction *a = [[Attraction alloc] init]; 
    a.address = [(Attraction *)[attractions objectAtIndex:i] address]; 
    a.city = [(Attraction *)[attractions objectAtIndex:i] city]; 
    a.state = [(Attraction *)[attractions objectAtIndex:i] state]; 

    NSString *address = [NSString stringWithFormat:@"%@,%@,%@", a.address, a.city, a.state]; 

    NSString *theAddress = [address stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]; 

    NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%@&output=csv", theAddress]; 

    NSString *locationString = [[NSString alloc] initWithContentsOfURL:[NSURL URLWithString:urlString] usedEncoding:nil error:nil]; 

    //NSLog(@"%@", locationString); 

    [[attractions objectAtIndex:i] setLocation:[[CLLocation alloc] initWithLatitude:43.1330340 longitude:-77.6376329]]; 

    NSLog(@"Attraction location = %@", [[attractions objectAtIndex:i] location]); 

    [self.mv addAnnotation:[self.attractions objectAtIndex:i]]; 

    NSLog(@"Mapview has %i annotations.", self.mv.annotations.count); 

} 

}

這裏的Attraction.h文件：

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

@interface Attraction : NSObject<MKAnnotation> 

@property(nonatomic,assign)int attractionID; 
@property(nonatomic,copy)NSString *name; 
@property(nonatomic,copy)NSString *address; 
@property(nonatomic,copy)NSString *description; 
@property(nonatomic,copy)NSString *city; 
@property(nonatomic,copy)NSString *state; 
@property(nonatomic,copy)CLLocation *location; 

+ (id)attraction; 
- (id)initWithID:(int)a_id name:(NSString *)a_name address:(NSString *)a_address description:(NSString*)a_description city:(NSString*)a_city state:(NSString *)a_state; 

@end

而這裏的Attraction.m文件：

#import "Attraction.h" 

@implementation Attraction 

@synthesize attractionID, name, address, description, city, state, location; 

- (CLLocationCoordinate2D)coordinate{ 
return self.location.coordinate; 
} 

- (NSString *)title{ 
return self.name; 
} 

- (NSString *)subtitle{ 
return self.name; 
} 

#pragma mark - 
+ (id)attraction { 
return [[Attraction alloc] init ]; 
} 

- (id)initWithID:(int)a_id name:(NSString *)a_name address:(NSString *)a_address description:(NSString*)a_description city:(NSString*)a_city state:(NSString *)a_state { 

self = [super init]; 
self.attractionID = a_id; 
self.address = a_address; 
self.name = a_name; 
self.description = a_description; 
self.city = a_city; 
self.state = a_state; 

return self; 

} 

- (id)init 
{ 
return [self initWithID:0 name:@"TBD" address:@"TBD" description:@"TBD" city:@"TBD" state:@"TBD"]; 
} 

@end

任何幫助，將不勝感激。謝謝。

來源

2012-02-15 Scott Douglass

self.attractions是否與景點相同？你確定self.mv不是零嗎？ – sch 2012-02-15 22:04:42

是的self.attractions是一樣的景點，我改變它，看看它有沒有影響，它沒有。我試圖找出它，但它看起來像self.mv是零，我不知道爲什麼。我把它掛在故事板上，所以我不知道爲什麼它是零。 – 2012-02-15 23:04:42

我設法弄清楚了。我有一個協議來更新地圖視圖的吸引力數據，以及它調用forwardGeoocoderFoundLocation方法的方法，該方法在viewDidLoad之前。我在viewDidLoad中調用了該方法，現在工作正常。謝謝！ – 2012-02-15 23:08:43

如果self.mv是nil，如您確認，那麼self.mv.annotations.count返回nil（或0，或類似的東西）。當您將其格式設置爲"%i"時，記錄爲0。

但是，您提交的代碼中沒有任何內容會導致它爲零，因此您必須在代碼的其他部分查找原因。

來源

2012-02-15 23:12:29 sch

謝謝，當我調用該方法將註釋添加到地圖時，該視圖未加載，因此無法。我發現什麼是錯誤的，現在正在工作！ – 2012-02-16 00:12:30

MKAnnotations沒有被添加到mapview

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