前回の続き：

[iPhone] Map Kitで遊ぼう：地図を出して現在位置にピンを立てる
http://blog.s21g.com/articles/1596

参考：

Drawing polyines or routes on a MKMapView (as an MKAnnotationView) – Part 2
http://spitzkoff.com/craig/?p=108

###MKAnnotationを実装するクラスを作成
MyAnnotation.h
rails>>
#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>

@interface MyAnnotation : NSObject {
CLLocationCoordinate2D _coordinate;
}

@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;

-(id)initWithCoordinate:(CLLocationCoordinate2D) coordinate;

@end
<<--

MyAnnotation.m
rails>>
#import "MyAnnotation.h"

@implementation MyAnnotation

@synthesize coordinate=_coordinate;

-(id)initWithCoordinate:(CLLocationCoordinate2D) c{
_coordinate=c;
return self;
}

@end
<<--

###ViewControllerでMKMapViewDelegateを実装
ポイントとしては

• .hでMKMapViewDelegateを実装宣言
• _mapView.delegate = self;
• -(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id )annotationを実装
• MyAnnotationなら画像を設定する：
  if([annotation isKindOfClass:[MyAnnotation class]]) {
  annotationView.image = [UIImage imageNamed:@"some.png"];

本当はMKAnnotationViewを派生して、MyAnnotationViewを作るのがベターなんですけど省略しています。

MapTutorialViewController.h
rails>>
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface MapTutorialViewController : UIViewController {
MKMapView *_mapView;
}
@end
<<--

MapTutorialViewController.m
rails>>
#pragma mark MKMapViewDelegate

• (MKAnnotationView *)mapView:(MKMapView )mapView viewForAnnotation:(id )annotation{
  MKAnnotationView annotationView;
  NSString identifier = @"Pin";
  annotationView = (MKPinAnnotationView)[_mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
  if(nil == annotationView) {
  annotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
  }
  if([annotation isKindOfClass:[MyAnnotation class]]) {
  annotationView.image = [UIImage imageNamed:@"some.png"]; //地図に表示したい画像を設定
  }
  return annotationView;
  }

• (void)addSomeAnnotations {
  //a location
  double latitude = 37.331688999999997;
  double longitude = -122.030731;
  CLLocationCoordinate2D _location;
  _location.latitude = latitude;
  _location.longitude = longitude;

  CLLocationCoordinate2D location1;
  MyAnnotation *annotation;

  location1.latitude = _location.latitude+0.1;
  location1.longitude = _location.longitude+0.1;
  annotation =[[MyAnnotation alloc] initWithCoordinate:location1];
  [_mapView addAnnotation:annotation];

  location1.latitude = _location.latitude+0.5;
  location1.longitude = _location.longitude+0.5;
  annotation =[[MyAnnotation alloc] initWithCoordinate:location1];
  [_mapView addAnnotation:annotation];

}

• (void)viewDidLoad {
  [super viewDidLoad];

  _mapView = [[MKMapView alloc] initWithFrame:self.view.bounds];
  _mapView.showsUserLocation=TRUE;
  _mapView.delegate = self;
  [self.view addSubview:_mapView];

  [self addSomeAnnotations];

}

<<--