iPhoneアプリで位置情報と地図を使うための基礎知識：iOSでジオ（GEO）プログミラング入門（1）（2/3 ページ）

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
 
@interface GeoPhotoViewController : UIViewController <CLLocationManagerDelegate> {
    CLLocationManager *locationManager;
}
 
@property (nonatomic, retain) CLLocationManager *locationManager;
 
@end

#import "GeoPhotoViewController.h"
 
@implementation GeoPhotoViewController
@synthesize locationManager;
 
- (void)viewDidLoad {
    [super viewDidLoad];
    locationManager = [[CLLocationManager alloc] init];
 
    // 位置情報サービスが利用できるかどうかをチェック
    if ([CLLocationManager locationServicesEnabled]) {
        locationManager.delegate = self; // ……【1】
        // 測位開始
        [locationManager startUpdatingLocation];
    } else {
        NSLog(@"Location services not available.");
    }
}
 
// 位置情報更新時
- (void)locationManager:(CLLocationManager *)manager 
didUpdateToLocation:(CLLocation *)newLocation 
fromLocation:(CLLocation *)oldLocation {
 
    //緯度・経度を出力
    NSLog(@"didUpdateToLocation latitude=%f, longitude=%f",
        [newLocation coordinate].latitude,
        [newLocation coordinate].longitude);
}
 
// 測位失敗時や、5位置情報の利用をユーザーが「不許可」とした場合などに呼ばれる
- (void)locationManager:(CLLocationManager *)manager 
didFailWithError:(NSError *)error{
    NSLog(@"didFailWithError");
}
 
- (void)dealloc {
    [locationManager release];
    [super dealloc];
}
@end

-(void) onResume;
-(void) onPause;

-(void) onResume {
    if (nil == locationManager && [CLLocationManager locationServicesEnabled])
        [locationManager startUpdatingLocation]; //測位再開
}
 
-(void) onPause {
    if (nil == locationManager && [CLLocationManager locationServicesEnabled])
        [locationManager stopUpdatingLocation]; //測位停止
}

- (void)applicationWillResignActive:(UIApplication *)application {
    NSLog(@"applicationWillResignActive");
    [viewController onPause];
}
 
- (void)applicationDidBecomeActive:(UIApplication *)application {
    NSLog(@"applicationDidBecomeActive");
    [viewController onResume];
}