MKAnnotation，简单示例

Question

有MKAnnotation 的简单示例项目吗？我不知道在“addAnnotation”要传递什么，因为它想要一些“id<Annotation>”。 开发者网站上的示例都是数组或解析器左右，我只需要一个非常简单的示例来首先了解整个事情是如何工作的。

提前谢谢..

编辑：

我开设了一个班级Pin。在 .h 中它写道

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

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

@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
@property (nonatomic, readonly) NSString *title;
@property (nonatomic, readonly) NSString *subTitle;

- (id)initWithCoordinates:(CLLocationCoordinate2D)location placeName:(NSString *)placeName description:(NSString *)description;
@end

根据 onnoweb 的回答。

在Pin.m中，我是这样实现的，根据不同的例子：

#import "Pin.h"

@implementation Pin

@synthesize title, subTitle;

- (CLLocationCoordinate2D) coordinate {
CLLocationCoordinate2D coords;
coords.latitude = coordinate.latitude; //i want it that way
coords.longitude =  7.1352260; //this way it works

return coords;

- (NSString *) title {
return @"Thats the title";
}

- (NSString *) subtitle {
return @"Thats the sub";
}

- (id)initWithCoordinates:(CLLocationCoordinate2D)location placeName:(NSString *)placeName description:(NSString *)description {

return self;
}

- (void) dealloc {
[super dealloc];
}

@end

所以如果我手动设置坐标，正如评论中所指出的，它可以工作。但我希望能够像在第一条评论中那样动态设置值。我尝试了各种方法，但都没有奏效。由于您没有指定- (CLLocationCoordinate2D) coordinate，因此我尝试仅合成coordinate，但这样也行不通。

你能给我看看你的 MapPin.m 吗？

编辑 2：

我设置mapCenter喜欢

- (void)viewWillAppear:(BOOL)animated {
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
self.locationManager.delegate = self;
[self.locationManager startUpdatingLocation];

CLLocation *curPos = locationManager.location;
location = curPos.coordinate;

CLLocationCoordinate2D mapCenter;
mapCenter.latitude =  location.latitude;
mapCenter.longitude = location.longitude;

MKCoordinateSpan mapSpan;
mapSpan.latitudeDelta = 0.005;
mapSpan.longitudeDelta = 0.005;

MKCoordinateRegion mapRegion;
mapRegion.center = mapCenter;
mapRegion.span = mapSpan;

mapKitView.region = mapRegion;
mapKitView.mapType = MKMapTypeStandard;
mapKitView.showsUserLocation=TRUE;
}

这有什么问题吗？

Answer 1

您需要有一个实现MKAnnotation 协议的类。这是我的一个项目中的一个 sn-p：

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

@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
@property (nonatomic, readonly) NSString *title;
@property (nonatomic, readonly) NSString *subtitle;

- (id)initWithCoordinates:(CLLocationCoordinate2D)location placeName:(NSString *)placeName description:(NSString *)description;

@end

然后，您将在哪里创建地图：

pin = [[MapPin alloc] initWithCoordinates:[track startCoordinates] placeName:@"Start" description:@""];
[map addAnnotation:pin];

编辑：

这里是实现：

@implementation MapPin

@synthesize coordinate;
@synthesize title;
@synthesize subtitle;

- (id)initWithCoordinates:(CLLocationCoordinate2D)location placeName:placeName description:description {
    self = [super init];
    if (self != nil) {
        coordinate = location;
        title = placeName;
        [title retain];
        subtitle = description;
        [subtitle retain];
    }
    return self;
}

- (void)dealloc {
    [title release];
    [subtitle release];
    [super dealloc];
}


@end

希望这会有所帮助， 小野。