地图应用的简单示例

首先，需要将CoreLocation.framework和MapKit.framework加入到项目中。

 

头文件：

 

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>

@interface LocationViewController : UIViewController <CLLocationManagerDelegate> {
	CLLocationManager *locationManager;
	CLLocation *myLocation;	
	IBOutlet UIButton *getLocationBtn;
	IBOutlet UILabel *latitudeLabel;
	IBOutlet UILabel *longitudeLabel;
	IBOutlet MKMapView *mapView;        
}

@property (nonatomic, retain) CLLocationManager *locationManager;
@property (nonatomic, retain) CLLocation *myLocation;
@property (nonatomic, retain) UIButton *getLocationBtn;
@property (nonatomic, retain) UILabel *latitudeLabel;
@property (nonatomic, retain) UILabel *longitudeLabel;
@property (nonatomic, retain) MKMapView *mapView;

- (IBAction) getLocationBtnClicked:(id) sender;
- (void) initMapView;
- (void) initLocation;

@end

 

实现文件：

 

#import "LocationViewController.h"

@implementation LocationViewController

@synthesize locationManager;
@synthesize myLocation;
@synthesize getLocationBtn;
@synthesize latitudeLabel;
@synthesize longitudeLabel;
@synthesize mapView;

- (void)viewDidLoad {
	[self initMapView];
	[self initLocation];
    [super viewDidLoad];
}

//初始化地图显示参数
- (void) initMapView {
	//设定显示中心经纬度
	CLLocationCoordinate2D theCoordinate;
	theCoordinate.latitude = 38.148926;
	theCoordinate.longitude = -120.715542;
	//设定显示范围
	MKCoordinateSpan theSpan;
	theSpan.latitudeDelta = 0.1;
	theSpan.longitudeDelta = 0.1;
	//设置地图显示的中心及范围
	MKCoordinateRegion theRegion;
	theRegion.center = theCoordinate;
	theRegion.span = theSpan;
	//设置地图显示的类型及根据范围进行显示
	[self.mapView setMapType:MKMapTypeStandard];	
	[mapView setRegion:theRegion];
	[mapView regionThatFits:theRegion];
	//定位后在地图上用蓝色点显示用户的位置
	mapView.showsUserLocation = YES;
}

//初始化定位相关参数
- (void) initLocation {
	self.locationManager = [[CLLocationManager alloc] init];
	//设置代理
	locationManager.delegate = self;
	//设置需要的定位精度
	locationManager.desiredAccuracy = kCLLocationAccuracyBest;	
	latitudeLabel.text = @"";
	longitudeLabel.text = @"";
}

- (IBAction) getLocationBtnClicked:(id) sender {
	latitudeLabel.text = @"";
	longitudeLabel.text = @"";
	//启动定位
	[locationManager startUpdatingLocation];
}

- (void)dealloc {
	[locationManager release];
	[myLocation release];
	[getLocationBtn release];
	[latitudeLabel release];
	[longitudeLabel release];
	[mapView release];
    [super dealloc];
}

//代理方法
#pragma mark -
#pragma mark CLLocationManagerDelegate Methods
//确定当前位置和位置更新了时调用这个方法
- (void)locationManager:(CLLocationManager *)manager 
	didUpdateToLocation:(CLLocation *)newLocation 
		   fromLocation:(CLLocation *)oldLocation
{
	//获得定位点的纬度信息
	NSString *latitudeString = [[NSString alloc] initWithFormat:@"%g", newLocation.coordinate.latitude];
	latitudeLabel.text = latitudeString;
	[latitudeString release];
	//获得定位点的经度信息
	NSString *longitudeString = [[NSString alloc] initWithFormat:@"%g", newLocation.coordinate.longitude];
	longitudeLabel.text = longitudeString;
	[longitudeString release];
	//停止定位
	[locationManager stopUpdatingLocation];
	//把地图中心移动到定位到的这个点
	[mapView setCenterCoordinate:newLocation.coordinate animated:YES];
	//重新设置地图显示的区域
	MKCoordinateSpan newSpan;
	newSpan.latitudeDelta = 0.05;
	newSpan.longitudeDelta = 0.05;
	MKCoordinateRegion newRegion;
	newRegion.center = newLocation.coordinate;
	newRegion.span = newSpan;
	[mapView setRegion:newRegion animated:YES];
}

//位置查询遇到错误时调用这个方法
- (void)locationManager:(CLLocationManager *)manager 
	   didFailWithError:(NSError *)error
{
	NSString *errorType = (error.code == kCLErrorDenied) ? 
    @"Access Denied" : @"Unknown Error";
    UIAlertView *alert = [[UIAlertView alloc] 
                          initWithTitle:@"Error getting Location" 
                          message:errorType 
                          delegate:nil 
                          cancelButtonTitle:@"OK" 
                          otherButtonTitles:nil];
    [alert show];
    [alert release];
}

@end