从JSON数组中拉出MKAnnotation字幕

Question

I am trying to add a subtitle to my MKAnnotation by pulling it from a JSON array. I am able to get the title, and coordinates with my view controller like below, but I can't figure out what to do to get the subtitle to be pulled from the JSON key "cityName". Any help would be great! Thank you!

MapViewController.m

location.latitude = [dictionary[@"placeLatitude"] doubleValue];
location.longitude = [dictionary[@"placeLongitude"] doubleValue];  

newAnnotation = [[MapViewAnnotation alloc] initWithTitle:dictionary[@"placeName"]
                                               andCoordinate:location];

MapViewAnnotation.h

@interface MapViewAnnotation : NSObject <MKAnnotation> {
NSString *title;
CLLocationCoordinate2D coordinate; 
}

@property (nonatomic, copy) NSString *title;
@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
@property (nonatomic, copy) NSString *subtitle;
- (id)initWithTitle:(NSString *)ttl andCoordinate:(CLLocationCoordinate2D)c2d;
@end

MapViewAnnotation.m

#import "MapViewAnnotation.h"
@implementation MapViewAnnotation
@synthesize title, coordinate, subtitle;

- (id)initWithTitle:(NSString *)ttl andCoordinate:(CLLocationCoordinate2D)c2d {
title = ttl;
coordinate = c2d;
subtitle = [SUBTITLE PULLED FROM JSON]
return self;
}
@end

Answer 1

What's the problem here ? Just do exactly what you're doing with the title property.

Answer 2

Since there might be situations where you don't initialize every single property your annotation has I'd advise against putting them all into the init method.

Just do this and you won't need to change MapViewAnnotation.m or h

location.latitude = [dictionary[@"placeLatitude"] doubleValue];
location.longitude = [dictionary[@"placeLongitude"] doubleValue];  

newAnnotation = [[MapViewAnnotation alloc] initWithTitle:dictionary[@"placeName"]
                                           andCoordinate:location];
newAnnotation.subtitle = dictionary[@"cityName"];