iOS应用开发－地图定位

iOS开发中经常会涉及到地图开发，比较长见的如打车软件、点评软件、团购软件、旅游软件还有许多社交软件，都会涉及。地图开发主要有以下几个步骤：

导入markit、action包－》生成MKMapView对象－》设置MKMapView代理－》实现代理。

一、显示以某个区域为中心的地图

  1、生成MKMapView对象

     _mapView = [[MKMapViewalloc] initWithFrame:CGRectMake(0,64, width, height - 64 - 49 - 50)];

  2、设置MapView代理方法：

    _mapView.delegate =self;

    [self.viewaddSubview:_mapView];

  3、定义一个坐标

    CLLocationCoordinate2D coordinate = {31.19316,121.43154};

  4、设置缩放级别

    MKCoordinateSpan span = {0.005,0.005};

    MKCoordinateRegion region = {coordinate, span};

    [_mapView setRegion:region];

二、定位用户位置

开发路线：MKMapView设置showsUserLocation＝YES可以显示定位＝》创建CLLocationManager ＝》开始定位＝》实现定位代理方法。

1.创建CLLocationManager方法

        self.locationManager = [[CLLocationManageralloc] init];

2.设置CLLocationManager代理      

  self.locationManager.delegate =self;

3.如果是ios8以上系统，还需要请求用户授权。

 首先需在target info中增加NSLocationWhenInUseUsageDescription 字段，其次请求用户授权

  if ([[UIDevicecurrentDevice].systemVersiondoubleValue] >= 8.0) {// 如果系统设备>= 8.0

        [self.locationManagerrequestWhenInUseAuthorization] ;

    } 

然后在授权状态改变的代理方法中，处理授权状态的改变。

- (void) locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status {

    if (status ==kCLAuthorizationStatusNotDetermined) {

        NSLog(@"等待用户授权");

    }elseif (status ==kCLAuthorizationStatusAuthorizedAlways ||

              status == kCLAuthorizationStatusAuthorizedWhenInUse) {

      4.  [self.locationManagerstartUpdatingLocation];

        

    } else {

        NSLog(@"授权失败");

    }

}

4.开始定为操作

 [self.locationManager startUpdatingLocation];

5.实现定位代理方法。定位成功或失败根据代理来设置

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error

{

   //定位完成后停止定位

    [self.locationManagerstopUpdatingLocation];

    NSLog(@"%@", error.description);

}

- (void)locationManager:(CLLocationManager *)manager

    didUpdateToLocation:(CLLocation *)newLocation

           fromLocation:(CLLocation *)oldLocation

{

    [self.locationManagerstopUpdatingLocation];

    self.currentLocation = newLocation;

   

   NSString locationStr = [NSStringstringWithFormat:@"(%f,%f)", newLocation.coordinate.latitude,

                           newLocation.coordinate.longitude];

}

两点距离：  CLLocationDistance distance = [newLocation distanceFromLocation:oldLocation];通常会出现于 你与那个地方相距多远。

完整代码：

#import <UIKit/UIKit.h>

#import "BLBaseViewController.h"

#import <MapKit/MapKit.h>

#import <CoreLocation/CoreLocation.h>

@interface LocationViewController：UIViewController
 <CLLocationManagerDelegate,MKMapViewDelegate>

{

    MKMapView           *_mapView;

    UILabel             *_locationLabel;    

    NSMutableArray      *_annotations;

}

@property (nonatomic,strong) CLLocationManager *locationManager;

@end

@interface LocationViewController ()

@end

@implementation LocationViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    CGFloat width =self.view.bounds.size.width;

    CGFloat height =self.view.bounds.size.height;

    

    

    _mapView = [[MKMapViewalloc] initWithFrame:CGRectMake(0,64, width, height - 64 - 49 - 50)];

    _mapView.showsUserLocation =YES;

    _mapView.delegate =self;

    [self.viewaddSubview:_mapView];

    

    CLLocationCoordinate2D coordinate = {31.19316,121.43154};

    MKCoordinateSpan span = {0.05,0.05};

    MKCoordinateRegion region = {coordinate, span};

    [_mapView setRegion:region];

    

    _locationLabel = [[UILabelalloc] initWithFrame:CGRectMake(0,_mapView.frame.origin.y +_mapView.frame.size.height, width,50)];

    _locationLabel.textAlignment =NSTextAlignmentCenter;

    _locationLabel.backgroundColor = [UIColorcyanColor];

    _locationLabel.text =@"user's location.";

    [self.viewaddSubview:_locationLabel];

    

    UIBarButtonItem *locationButton

    = [[UIBarButtonItemalloc] initWithTitle:@"定位"

                                       style:UIBarButtonItemStyleBordered

                                      target:self

                                      action:@selector(locationButtonClicked:)];

    self.navigationItem.leftBarButtonItem = locationButton;

｝

- (void)locationButtonClicked:(id)sender

{

    if (self.locationManager ==nil) {

        self.locationManager = [[CLLocationManageralloc] init];

        self.locationManager.delegate =self;

    }

    if ([[UIDevicecurrentDevice].systemVersiondoubleValue] >= 8.0) {// 如果系统设备>= 8.0

        [self.locationManagerrequestWhenInUseAuthorization] ;

    } else {

        // 2. 开始定位

        [self.locationManagerstartUpdatingLocation] ;

    }

}

#pragma mark - CLLocationManagerDelegate methods

- (void) locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status {

    if (status ==kCLAuthorizationStatusNotDetermined) {

        NSLog(@"等待用户授权");

    }elseif (status ==kCLAuthorizationStatusAuthorizedAlways ||

              status == kCLAuthorizationStatusAuthorizedWhenInUse) {

        [self.locationManagerstartUpdatingLocation];

        

    } else {

        NSLog(@"授权失败");

    }

}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error

{

    [self.locationManagerstopUpdatingLocation];

    NSLog(@"%@", error.description);

}

- (void)locationManager:(CLLocationManager *)manager

    didUpdateToLocation:(CLLocation *)newLocation

           fromLocation:(CLLocation *)oldLocation

{

    [self.locationManagerstopUpdatingLocation];

    self.currentLocation = newLocation;

    _locationLabel.text = [NSStringstringWithFormat:@"(%f,%f)", newLocation.coordinate.latitude,

                           newLocation.coordinate.longitude];

}