在程序中使用GPS定位
这一回简单地介绍一下GPS的使用方法。使用GPS大致分下面两步。
1.添加 CoreLocation.framework。
2.生成 CLLocationManager 测量位置。
测试代码如下：
// LocationViewCtrl.h#import <UIKit/UIKit.h>#import <CoreLocation/CoreLocation.h>@interface LocationViewCtrl : UIViewController <CLLocationManagerDelegate>{ CLLocationManager *man;}@property(nonatomic, retain) CLLocationManager *man;@endLocationViewCtrl.m#import "LocationViewCtrl.h"#import <CoreLocation/CoreLocation.h>@implementation LocationViewCtrl@synthesize man;- (void)viewDidLoad { [super viewDidLoad]; man = [[CLLocationManager alloc] init]; // 如果可以利用本地服务时 if([man locationServicesEnabled]){ // 接收事件的实例 man.delegate = self; // 发生事件的的最小距离间隔（缺省是不指定） man.distanceFilter = kCLDistanceFilterNone; // 精度 (缺省是Best) man.desiredAccuracy = kCLLocationAccuracyBest; // 开始测量 [man startUpdatingLocation]; }}// 如果GPS测量成果以下的函数被调用- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{ // 取得经纬度 CLLocationCoordinate2D coordinate = newLocation.coordinate; CLLocationDegrees latitude = coordinate.latitude; CLLocationDegrees longitude = coordinate.longitude; // 取得精度 CLLocationAccuracy horizontal = newLocation.horizontalAccuracy; CLLocationAccuracy vertical = newLocation.verticalAccuracy; // 取得高度 CLLocationDistance altitude = newLocation.altitude; // 取得时刻 NSDate *timestamp = [newLocation timestamp]; // 以下面的格式输出 format: <latitude>, <longitude>> +/- <accuracy>m @ <date-time> NSLog([newLocation description]); // 与上次测量地点的间隔距离 if(oldLocation != nil){ CLLocationDistance d = [newLocation getDistanceFrom:oldLocation]; NSLog([NSString stringWithFormat:@"%f", d]); }}// 如果GPS测量失败了，下面的函数被调用- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error{ NSLog([error localizedDescription]);}...