一个用来定位当前城市的单例

整理了一个获取定位当前城市的单例类

ZWMapHelper.h

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

//定位成功回调
typedef void(^ReturnCurrentCity)(NSString *currentcity);

@interface ZWMapHelper : NSObject

/// 单例实例
+ (ZWMapHelper *) sharedInstance;

/// 开始定位并获得位置相关信息
- (void)startLocationAndGetPlaceInfo;

/// 地球坐标系(真实GPS坐标)转火星坐标（高德坐标）
- (CLLocationCoordinate2D)wgs84ToGcj02:(CLLocationCoordinate2D)wgs84Coor;
/// 火星坐标转地球坐标系
- (CLLocationCoordinate2D)gcj02ToWgs84:(CLLocationCoordinate2D)gcj02Coor;
/// 坐标是否在中国内
- (BOOL)isInChina:(double)lat lon:(double)lon;
@property(nonatomic,copy)ReturnCurrentCity  returnBlock;

@end

ZWMapHelper.m

#import "ZWMapHelper.h"
static ZWMapHelper *_sharedInstance = nil;

@interface ZWMapHelper ()<CLLocationManagerDelegate>
{
BOOL isCity;//判断是否请求到当前城市
}
@property (strong, nonatomic) CLLocationManager *locationManager;
@property (strong, nonatomic) CLPlacemark *currPlacemark;

@property(strong,nonatomic)NSTimer *timer;
@end

@implementation ZWMapHelper

#pragma mark - Class life cycle method
+ (ZWMapHelper *) sharedInstance
{
@synchronized(self)
{
if (_sharedInstance == nil)
{
_sharedInstance = [[super allocWithZone:NULL] init];
}
}
return _sharedInstance;
}

+ (id)allocWithZone:(NSZone *)zone
{
@synchronized(self)
{
if(_sharedInstance == nil)
{
_sharedInstance = [super allocWithZone:zone];
return _sharedInstance;
}
}

return nil;
}

- (id)init
{
if ((self=[super init]))
{
//开始定位并获得位置相关信息(如国家等)
//        [self startLocationAndGetPlaceInfo];
isCity=NO;
}
return self;
}

/// 开始定位并获得位置相关信息(如国家等)
- (void)startLocationAndGetPlaceInfo
{
if (self.currPlacemark) return; //如果已取得位置信息则退出

if (!self.locationManager)
{
// 1. 实例化定位管理器
self.locationManager = [[CLLocationManager alloc] init];
// 2. 设置代理
self.locationManager.delegate = self;
// 3. 定位精度
[self.locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
// 4.请求用户权限：分为：?只在前台开启定位?在后台也可定位，
//注意：建议只请求?和?中的一个，如果两个权限都需要，只请求?即可，
//??这样的顺序，将导致bug：第一次启动程序后，系统将只请求?的权限，?的权限系统不会请求，只会在下一次启动应用时请求?
self.locationManager.distanceFilter = kCLDistanceFilterNone; //1.0f;
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8) {
[_locationManager requestWhenInUseAuthorization];//?只在前台开启定位
//需在info.plist中配置
//            [self.locationManager requestAlwaysAuthorization];//?在后台也可定位
}
// 5.iOS9新特性：将允许出现这种场景：同一app中多个location manager：一些只能在前台定位，另一些可在后台定位（并可随时禁止其后台定位）。
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 9) {
self.locationManager.allowsBackgroundLocationUpdates = YES;
}
self.locationManager.pausesLocationUpdatesAutomatically = NO; //NO表示一直请求定位服务
// 6. 更新用户位置
[self.locationManager startUpdatingLocation];

}

//开始定位
[self.locationManager startUpdatingLocation];
}

//响应当前位置的更新，在这里记录最新的当前位置
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
CLLocation *newLocation = [locations lastObject];

//    //只定位一次
[manager stopUpdatingLocation];
//地球坐标转到火星坐标才能查询出真实地址
CLLocationCoordinate2D gcg02Coord = [self wgs84ToGcj02:newLocation.coordinate];
if (gcg02Coord.latitude>=0 && gcg02Coord.longitude>=0) {
[[NSUserDefaults standardUserDefaults] setObject:[NSString stringWithFormat:@"%f",gcg02Coord.longitude] forKey:@"longitude"];
[[NSUserDefaults standardUserDefaults] setObject:[NSString stringWithFormat:@"%f",gcg02Coord.latitude] forKey:@"latitude"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
CLLocation *convertedLoc = [[CLLocation alloc] initWithLatitude:gcg02Coord.latitude longitude:gcg02Coord.longitude];

CLGeocoder *geocoder = [[CLGeocoder alloc] init];

[geocoder reverseGeocodeLocation:convertedLoc completionHandler:^(NSArray *placemarks, NSError *error)
{
if ([placemarks count] > 0 && error == nil) {
CLPlacemark *placemark = [placemarks objectAtIndex:0];
NSArray *languages = [NSLocale preferredLanguages];
NSString *currentLanguage = [languages objectAtIndex:0];
NSString *language;
//判断模拟器的语言环境
if (currentLanguage&&![currentLanguage isKindOfClass:[NSNull class]]) {
if (currentLanguage.length>=@"zh-Hans".length) {
language=[currentLanguage substringToIndex:@"zh-Hans".length];
}
}
NSString *currentCity;
if (language)
{
if ([language isEqualToString:@"zh-Hans"])
{
//因为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
if (placemark.locality)
{
currentCity = [placemark.locality substringToIndex:placemark.locality.length - 1];
}
else
{
currentCity = [placemark.administrativeArea substringToIndex:placemark.administrativeArea.length - 1];
}
}
else
{   //本地是英文时
if (placemark.locality)
{
currentCity = placemark.locality;
}
else
{
currentCity = placemark.administrativeArea;
}

}

if (currentCity) {

if (self.returnBlock&&isCity!=YES) {
isCity=YES;
self.returnBlock(currentCity);
}
}
}
}
}];
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
//只定位一次
[manager startUpdatingLocation];

}

#pragma mark - 地球坐标(原始GPS坐标)和火星坐标（高德/Google中国）互转
const double g_pi = 3.14159265358979324;
const double g_a = 6378245.0;
const double g_ee = 0.00669342162296594323;
- (CLLocationCoordinate2D)wgs84ToGcj02:(CLLocationCoordinate2D)wgs84Coor
{

CLLocationCoordinate2D gcj02Coor;

if (outOfChina(wgs84Coor.latitude, wgs84Coor.longitude)) {

gcj02Coor = wgs84Coor;

return gcj02Coor;

}

double dLat = transformLat(wgs84Coor.longitude-105.0, wgs84Coor.latitude-35.0);

double dLon = transformLon(wgs84Coor.longitude-105.0, wgs84Coor.latitude-35.0);

double radLat = wgs84Coor.latitude/180.0*g_pi;

double magic = sin(radLat);

magic = 1-g_ee*magic*magic;

double sqrtMagic = sqrt(magic);

dLat = (dLat * 180.0) / ((g_a * (1 - g_ee)) / (magic * sqrtMagic) * g_pi);

dLon = (dLon * 180.0) / (g_a / sqrtMagic * cos(radLat) * g_pi);

gcj02Coor = CLLocationCoordinate2DMake(wgs84Coor.latitude+dLat, wgs84Coor.longitude+dLon);

return gcj02Coor;

}

#pragma mark-火星坐标转地球坐标
- (CLLocationCoordinate2D)gcj02ToWgs84:(CLLocationCoordinate2D)gcj02Coor
{
double lon = gcj02Coor.longitude;
double lat = gcj02Coor.latitude;

CLLocationCoordinate2D coor = [self wgs84ToGcj02:gcj02Coor];

double lontitude = lon - (coor.longitude - lon);
double latitude = lat - (coor.latitude - lat);

return CLLocationCoordinate2DMake(latitude, lontitude);

}

#pragma mark-判断是中国还是外国
- (BOOL)isInChina:(double)lat lon:(double)lon
{
return outOfChina(lat, lon) ? NO : YES ;
}

#pragma mark-判断是中国还是外国
bool outOfChina(double lat, double lon)
{
//缓存中未拿到国家信息
if ([ZWMapHelper sharedInstance].currPlacemark) {

NSString *countryCode = [ZWMapHelper sharedInstance].currPlacemark.ISOcountryCode;
if (!countryCode || countryCode.length < 1) return false; //默认认为在中国

//
if ([countryCode isEqualToString:@"CN"] ) {
return false;
}
}

if (lon < 72.004 || lon > 137.8347)
return true;

if (lat < 0.8293 || lat > 55.8271)
return true;

return false;

}

#pragma mark-转换经度
double transformLat(double x, double y)
{

double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * sqrt(abs(x));

ret += (20.0 * sin(6.0 * x * g_pi) + 20.0 * sin(2.0 * x * g_pi)) * 2.0 / 3.0;

ret += (20.0 * sin(y * g_pi) + 40.0 * sin(y / 3.0 * g_pi)) * 2.0 / 3.0;

ret += (160.0 * sin(y / 12.0 * g_pi) + 320 * sin(y * g_pi / 30.0)) * 2.0 / 3.0;

return ret;

}

#pragma mark-转换纬度
double transformLon(double x, double y)
{

double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * sqrt(abs(x));

ret += (20.0 * sin(6.0 * x * g_pi) + 20.0 * sin(2.0 * x * g_pi)) * 2.0 / 3.0;

ret += (20.0 * sin(x * g_pi) + 40.0 * sin(x / 3.0 * g_pi)) * 2.0 / 3.0;

ret += (150.0 * sin(x / 12.0 * g_pi) + 300.0 * sin(x / 30.0 * g_pi)) * 2.0 / 3.0;

return ret;

}

注意：

如果要求在后台也可以定位，// [self.locationManager requestAlwaysAuthorization];//?在后台也可定位 把这行代码放开，并需在info.plist中配置如下：



调用方法：

ZWMapHelper *helper= [ZWMapHelper sharedInstance];
[helper startLocationAndGetPlaceInfo];
helper.returnBlock=^(NSString * currentcity){
NSLog(@"%@====>",currentcity);
};