CoreLocation是控制GPS硬件获取地理坐标信息的系统类库，而MapKit是系统地图的工具包，将两者结合使用可以实现不同的地图功能。
1.CoreLocation
在CoreLocation中，CLLocationManager是获取坐标的工具，创建如下：
if ([CLLocationManager locationServicesEnabled]) // 判断设备是否支持定位功能
{
NSLog(@"支持定位");
locManager = [[CLLocationManager alloc] init];
locManager.distanceFilter = ; // 过滤距离，以m为单位，越小更新越精确越快，但越耗电
locManager.desiredAccuracy = kCLLocationAccuracyBest; // 定位精确度，但耗电
locManager.delegate = self;
}
[locManager startUpdatingLocation]; // 设置好属性后，需要开始更新定位
CLLocationManager更新位置的代理方法如下，其中需要用到MKReverseGeocoder对经纬度进行解析，获取更直观详细的位置信息：
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
NSLog(@"%s",__func__);
NSLog(@"locs = %@",locations); CLLocation *newLoc = (CLLocation *)[locations objectAtIndex:]; // 位置信息 // 解析地理编码
MKReverseGeocoder *geo = [[MKReverseGeocoder alloc] initWithCoordinate:newLoc.coordinate]; // 解析经纬度（在IOS5中该方法过期了，需要用CLGeocoder）
geo.delegate = self;
[geo start];
}
MKReverseGeocoder解析经纬度后的代理方法：
// 反解析成功
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark
{
NSLog(@"国家：%@",placemark.country);
NSLog(@"市区：%@",placemark.locality);
} // 反解析失败
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFailWithError:(NSError *)error
{
}
2.MapKit
创建一个地图视图
mapView = [[MKMapView alloc] initWithFrame:self.view.bounds];
mapView.mapType = MKMapTypeStandard; // 地图显示类型，分标准，卫星，俯瞰
mapView.showsUserLocation = YES; // 是否显示当前位置
mapView.delegate = self;
要更新地图的话，可以在-locationManager:didUpdateLocations:中设置mapView的相关属性，如下：
// 设置地图区域，并确定地图细腻程度 ，放在解析经纬度之前
MKCoordinateRegion region; // 显示区域
region.center = newLoc.coordinate;
MKCoordinateSpan span; // 显示范围
span.latitudeDelta = 0.01f; // 细腻精度系数
span.longitudeDelta = 0.01f;
region.span = span;
mapView.region = region;
若要在地图中插入一个大头针的话，先要创建一个遵守MKAnnotation协议的类，
.h
#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h> @interface BIDDemoAnnotation : NSObject <MKAnnotation>
{
CLLocationCoordinate2D _coordinate;
} @property (readonly,nonatomic) CLLocationCoordinate2D coordinate;
@property (nonatomic, copy) NSString *title;
@property (nonatomic, copy) NSString *subtitle; - (id)initWithCoordinate2D:(CLLocationCoordinate2D)aCoordinate;
@end #####################################
.m
#import "BIDDemoAnnotation.h" @implementation BIDDemoAnnotation
@synthesize title = _title;
@synthesize subtitle = _subtitle;
@synthesize coordinate = _coordinate; - (id)initWithCoordinate2D:(CLLocationCoordinate2D)aCoordinate
{
if (self = [super init]) {
_coordinate = aCoordinate;
// self.coordinate = aCoordiante 错误，因为该属性为只读
}
return self;
}
@end
然后在反解析成功的代理方法中插入如下代码：
// [mapView removeAnnotations:mapView.annotations]; 清理已有的大头针 //根据经纬度创建大头针
BIDDemoAnnotation *ano = [[BIDDemoAnnotation alloc] initWithCoordinate2D:geocoder.coordinate]; //设置大头针的备注信息
ano.title = placemark.country;
ano.subtitle = placemark.locality; //插入到地图
[mapView addAnnotation:ano];
[ano release];
最后实现MKMapView的代理方法（原理和TableView一样，重用机制），设置大头针的样式等信息：
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation.title isEqualToString:@"Current Location"] == YES) {
return nil;
} static NSString *identifier = @"test";
MKPinAnnotationView *pinAnnotationView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if (pinAnnotationView == nil) {
pinAnnotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
}
pinAnnotationView.pinColor = MKPinAnnotationColorRed;
pinAnnotationView.animatesDrop = YES; UIButton *rightView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
pinAnnotationView.rightCalloutAccessoryView = rightView; UIButton *leftView = [UIButton buttonWithType:UIButtonTypeCustom];
leftView.frame = CGRectMake(, , , );
leftView.userInteractionEnabled = YES; pinAnnotationView.canShowCallout = YES;
pinAnnotationView.leftCalloutAccessoryView = leftView; return pinAnnotationView;
}