在负责显示 PIN 的实现类中，我保留了两个变量（标题和副标题），在此示例中，USA当我单击 PIN 时仅显示单词（标题）。
CLLocationCoordinate2D location2D = (CLLocationCoordinate2D){ .latitude = latitudeOfUserLocation, .longitude = longitudeOfUserLocation };
ManageAnnotations *annotation=[[ManageAnnotations alloc]initWithTitle:@"USA" adresseDuTheme:@"Colorado" coordinate:location2D];//only USA is displayed
annotation.pinColor = MKPinAnnotationColorRed; //or red or whatever
[self->mapView addAnnotation:annotation];
MKCoordinateSpan span={.latitudeDelta=1,.longitudeDelta=0.5};
MKCoordinateRegion region={location2D,span};
[mapView setRegion:region];
虽然，在 ManageAnnotations 类中，我为标题和副标题保留了两个变量。
@interface ManageAnnotations : NSObject<MKAnnotation>{
NSString *_libelle;
NSString *_adresse;
CLLocationCoordinate2D _coordinate;
}
//
@property(nonatomic,assign)MKPinAnnotationColor pinColor;
@property(copy)NSString *libelle;
@property(copy)NSString *adresse;
@property(nonatomic,readonly)CLLocationCoordinate2D coordinate;
-(id)initWithTitle:(NSString*)libelle adresseDuTheme:(NSString*)adresse coordinate:(CLLocationCoordinate2D)coordinate;
@end
#import "ManageAnnotations.h"
@implementation ManageAnnotations
@synthesize pinColor;
@synthesize libelle=_libelle;
@synthesize adresse=_adresse;
@synthesize coordinate=_coordinate;
-(id)initWithTitle:(NSString*)libelle adresseDuTheme:(NSString*)adresse coordinate:(CLLocationCoordinate2D)coordinate{
if((self=[super init])){
_libelle=[libelle copy];
_adresse=[adresse copy];
_coordinate=coordinate;
}
return self;
}
-(NSString*)title{
return _libelle;
}
-(NSString*)subTitle{
return _adresse;
}
@end