iOS 开发 如何获得用户当前位置(通过经纬度获得城市、省份等信息)

 iOS系统自带定位，用CLLocationManager就可以轻松的实现定位的操作，获得的是一组经纬度，当然，也可以根据给出的经纬度获取相应的省份、城市、街道等信息，下面就看一个根据经纬度获得城市的demo：

        因为获取经纬度需要CLLocationManager类，而这个类包含在CoreLocation框架中，获取城市信息需要mapKit框架，所以需要首先在工程中导入这两个框架：

导入框架的步骤：选择1.target――2.Build Phases――3.Link Binary With Libraries ――4.点击“+”号：如图所示步骤：

点击加号之后在搜索框里输入相应的框架，即可搜索到，如图所示

下面就该写代码了，首先在视图控制器中导入：

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

两个头文件，然后.m中的具体代码如下：

#import "ANNViewController.h"


@interface ANNViewController ()
@property (strong, nonatomic) IBOutlet UILabel *longitude;
@property (strong, nonatomic) IBOutlet UILabel *latitude;

@property (strong, nonatomic) IBOutlet UILabel *location;
@property (strong, nonatomic) CLLocationManager *locationManager;

@end

@implementation ANNViewController

- (void)viewDidLoad
{
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  self.view.backgroundColor = [UIColor whiteColor];
  
  //创建CLLocationManager对象
  self.locationManager = [[CLLocationManager alloc] init];
  //设置代理为自己
  self.locationManager.delegate = self;
  
}
- (IBAction)locationButton:(UIButton *)sender {
  [self.locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager
  didUpdateToLocation:(CLLocation *)newLocation
       fromLocation:(CLLocation *)oldLocation
{
  
  //将经度显示到label上
  self.longitude.text = [NSString stringWithFormat:@"%lf", newLocation.coordinate.longitude];
  //将纬度现实到label上
  self.latitude.text = [NSString stringWithFormat:@"%lf", newLocation.coordinate.latitude];
  
  // 获取当前所在的城市名
  CLGeocoder *geocoder = [[CLGeocoder alloc] init];
  //根据经纬度反向地理编译出地址信息
  [geocoder reverseGeocodeLocation:newLocation completionHandler:^(NSArray *array, NSError *error)
   {
     if (array.count > 0)
     {
       CLPlacemark *placemark = [array objectAtIndex:0];
       
       //将获得的所有信息显示到label上
       self.location.text = placemark.name;
       //获取城市
       NSString *city = placemark.locality;
       if (!city) {
         //四大直辖市的城市信息无法通过locality获得，只能通过获取省份的方法来获得（如果city为空，则可知为直辖市）
         city = placemark.administrativeArea;
       }
       NSLog(@"city = %@", city);
       
     }
     else if (error == nil && [array count] == 0)
     {
       NSLog(@"No results were returned.");
     }
     else if (error != nil)
     {
       NSLog(@"An error occurred = %@", error);
     }
   }];
  
  //系统会一直更新数据，直到选择停止更新，因为我们只需要获得一次经纬度即可，所以获取之后就停止更新
  [manager stopUpdatingLocation];
}

主要就是直辖市的城市获得需要拐个弯，iOS7添加了一个新的方法，代替了上面这个方法：

- (void)locationManager:(CLLocationManager *)manager
   didUpdateLocations:(NSArray *)locations
{
    NSLog(@"longitude = %f", ((CLLocation *)[locations
lastObject]).coordinate.longitude);
    NSLog(@"latitude = %f", ((CLLocation *)[locations lastObject]).coordinate.latitude);
    
    [manager stopUpdatingLocation];
}

后面的处理和上面的方法一样，大家可以看一下。

另外还有一些CLGeocoder的属性如下：

@property (nonatomic, readonly) NSDictionary *addressDictionary;

// address dictionary properties
@property (nonatomic, readonly) NSString *name; // eg. Apple Inc.
@property (nonatomic, readonly) NSString *thoroughfare; // street address, eg. 1 Infinite Loop
@property (nonatomic, readonly) NSString *subThoroughfare; // eg. 1
@property (nonatomic, readonly) NSString *locality; // city, eg. Cupertino
@property (nonatomic, readonly) NSString *subLocality; // neighborhood, common name, eg. Mission District
@property (nonatomic, readonly) NSString *administrativeArea; // state, eg. CA
@property (nonatomic, readonly) NSString *subAdministrativeArea; // county, eg. Santa Clara
@property (nonatomic, readonly) NSString *postalCode; // zip code, eg. 95014
@property (nonatomic, readonly) NSString *ISOcountryCode; // eg. US
@property (nonatomic, readonly) NSString *country; // eg. United States
@property (nonatomic, readonly) NSString *inlandWater; // eg. Lake Tahoe
@property (nonatomic, readonly) NSString *ocean; // eg. Pacific Ocean
@property (nonatomic, readonly) NSArray *areasOfInterest; // eg. Golden Gate Park