▼iPhoneプログラミングメモ▼
位置情報の取得

位置情報を取得するプログラムを作成する。


フレームワークの準備
CoreLocation.frameworkを追加。

ソースコードの記述
LocationEx.h 
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import <CoreLocation/CLLocationManagerDelegate.h>

//LocationExの宣言
@interface LocationEx : UIViewController <
    CLLocationManagerDelegate> {
    UILabel*            _label;
    CLLocationManager*  _locationManager;
    CLLocationDegrees   _latitude;
    CLLocationDegrees   _longitude;    
    CLLocationDirection _heading;
}
@end

LocationEx.m 
#import "LocationEx.h"

//LocationExの実装
@implementation LocationEx

//アラートの表示
- (void)showAlert:(NSString*)title text:(NSString*)text {
    UIAlertView* alert=[[[UIAlertView alloc] 
        initWithTitle:title message:text delegate:nil 
        cancelButtonTitle:@"OK" otherButtonTitles:nil] autorelease];
    [alert show];
}

//ラベルのリサイズ
- (void)resizeLabel:(UILabel*)label {
    CGRect frame=label.frame;
    frame.size=[label.text sizeWithFont:label.font 
        constrainedToSize:CGSizeMake(512,512)
        lineBreakMode:UILineBreakModeWordWrap];
    [label setFrame:frame];
}

//ラベルの生成
- (UILabel*)makeLabel:(CGPoint)pos 
    text:(NSString*)text font:(UIFont*)font {
    UILabel* label=[[[UILabel alloc] init] autorelease];         
    [label setText:text];
    [label setFont:font];
    [label setTextColor:[UIColor blackColor]];
    [label setBackgroundColor:[UIColor clearColor]];
    [label setTextAlignment:UITextAlignmentLeft];
    [label setNumberOfLines:0];
    [label setLineBreakMode:UILineBreakModeWordWrap];
    [self resizeLabel:label];
    return label;
}

//初期化
- (void)viewDidLoad {
    [super viewDidLoad];
    
    //ラベルの生成
    _label=[[self makeLabel:CGPointMake(0,0) 
        text:@"LocationEx" 
        font:[UIFont systemFontOfSize:16]] retain];
    [self.view addSubview:_label];    
    
    //情報
    _latitude =0.0f;
    _longitude=0.0f;
    _heading  =0.0f;
                
    //ロケーションマネージャーの生成
    _locationManager=[[CLLocationManager alloc] init];
    _locationManager.delegate=self;
        
    //位置情報通知の開始
    if ([_locationManager locationServicesEnabled]) {
        [_locationManager startUpdatingLocation];
    }        
        
    //方位情報通知の開始
    if ([_locationManager headingAvailable]) {
        [_locationManager startUpdatingHeading];            
    }

    //タイマーの生成        
    [NSTimer scheduledTimerWithTimeInterval:0.1f
        target:self
        selector:@selector(onTick:)
        userInfo:nil
        repeats:YES];
}

//メモリ解放
- (void)dealloc {
    //位置情報通知の停止
    [_locationManager stopUpdatingLocation];
    
    //方位情報通知の停止
    [_locationManager stopUpdatingHeading];
    
    //メモリ解放
    [_label release];
    _locationManager.delegate=nil;
    [_locationManager release];
    [super dealloc];
}

//定期処理
- (void)onTick:(NSTimer*)timer {
    //ラベルの更新
    NSMutableString* str=[NSMutableString string];
    [str appendString:@"LocationEx\n"];
    [str appendFormat:@"緯度:%+f\n",_latitude];
    [str appendFormat:@"経度:%+f\n",_longitude];
    [str appendFormat:@"方位:%+3.2f\n",_heading];
    [_label setText:str];
    [self resizeLabel:_label];
}

//位置情報更新時に呼ばれる
- (void)locationManager:(CLLocationManager*)manager 
    didUpdateToLocation:(CLLocation*)newLocation 
    fromLocation:(CLLocation*)oldLocation {
    //緯度・経度の取得
    CLLocationCoordinate2D coordinate=newLocation.coordinate;
    _latitude =coordinate.latitude;
    _longitude=coordinate.longitude;   
}

//位置情報取得失敗時に呼ばれる
- (void)locationManager:(CLLocationManager*)manager 
    didFailWithError:(NSError*)error {
    if ([error code]==kCLErrorDenied) {
        [self showAlert:@"" text:@"位置情報取得は許可されていません"];
    } else {
        [self showAlert:@"" text:@"位置情報取得に失敗しました"];
    }
}

//方位情報更新時に呼ばれる
- (void)locationManager:(CLLocationManager*)manager 
    didUpdateHeading:(CLHeading*)newHeading {
    //方位の取得
    _heading=newHeading.trueHeading;
}

//画面を端末の向きにあわせて回転
- (BOOL)shouldAutorotateToInterfaceOrientation:
    (UIInterfaceOrientation)orientation {
    return YES;
}
@end



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