地理编码与反地理编码

地理编码是把某个具体的位置计算为经纬度，反地理编码正好相反。

效果：通过输入框的搜索，也能定位到具体的位置。长按地图，就能获得某个位置的详细地址。

#import "ViewController.h"

#import <MapKit/MapKit.h>

@interface ViewController ()<CLLocationManagerDelegate,MKMapViewDelegate>

@property (nonatomic, strong) MKMapView * mapView;

@property (nonatomic, strong) CLLocationManager * locationManager;

@property (nonatomic, strong) UITextField * textField;

@property (nonatomic, strong) NSString * titleString;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

// 116.456011,39.941272

_mapView = [[MKMapView alloc] initWithFrame:self.view.bounds];

[_mapView setDelegate:self];

[_mapView setShowsUserLocation:YES];

[_mapView setMapType:MKMapTypeStandard];

[self.view addSubview:_mapView];

UILongPressGestureRecognizer * longpressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];

[_mapView addGestureRecognizer:longpressGestureRecognizer];

_textField = [[UITextField alloc] init];

[_textField setTranslatesAutoresizingMaskIntoConstraints:NO];

[_textField setBackgroundColor:[UIColor whiteColor]];

[self.view addSubview:_textField];

UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom];

[btn setBackgroundColor:[UIColor orangeColor]];

[btn setTitle:@"查找" forState:UIControlStateNormal];

[btn setTranslatesAutoresizingMaskIntoConstraints:NO];

[btn addTarget:self action:@selector(theBtnPressed:) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:btn];

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[_textField][btn(100)]-20-|"

options:0

metrics:nil

views:NSDictionaryOfVariableBindings(_textField,btn)]];

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[_textField(30)]-(-30)-[btn(30)]"

options:0

metrics:nil

views:NSDictionaryOfVariableBindings(_textField,btn)]];

//检测定位功能是否开启

if([CLLocationManager locationServicesEnabled]){

if(!_locationManager){

_locationManager = [[CLLocationManager alloc] init];

if([_locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]){

[_locationManager requestWhenInUseAuthorization];

[_locationManager requestAlwaysAuthorization];

}

//设置代理

[_locationManager setDelegate:self];

//设置定位精度

[_locationManager setDesiredAccuracy:kCLLocationAccuracyBest];

//设置距离筛选

[_locationManager setDistanceFilter:100];

//开始定位

[_locationManager startUpdatingLocation];

//设置开始识别方向

[_locationManager startUpdatingHeading];

}

}else{

UIAlertView * alertView = [[UIAlertView alloc] initWithTitle:nil

message:@"您没有开启定位功能"

delegate:nil

cancelButtonTitle:@"确定"

otherButtonTitles:nil, nil nil];

[alertView show];

}

}

//点击按钮执行此方法

- (void)theBtnPressed:(id)sender {

[_textField resignFirstResponder];

if([_textField.text length] == 0){

return;

}

[self geocoder:_textField.text];

}

#pragma mark LongPress

- (void)longPressed:(UILongPressGestureRecognizer *)recognizer {

if(recognizer.state == UIGestureRecognizerStateBegan){

CGPoint point = [recognizer locationInView:_mapView];

CLLocationCoordinate2D coordinate2D = [_mapView convertPoint:point toCoordinateFromView:_mapView];

[_mapView removeAnnotations:_mapView.annotations];

CLLocation * location = [[CLLocation alloc] initWithLatitude:coordinate2D.latitude longitude:coordinate2D.longitude];

[self reverseGeocoder:location];

// MKPointAnnotation * pointAnnotation = [[MKPointAnnotation alloc] init];

// [pointAnnotation setTitle:_titleString];

// [pointAnnotation setCoordinate:coordinate2D];

// [_mapView addAnnotation:pointAnnotation];

}

}

//授权状态发生改变的时候执行

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

switch(status){

case kCLAuthorizationStatusDenied:

{

UIAlertView * alertView = [[UIAlertView alloc] initWithTitle:nil

message:@"定位功能没有开启" delegate:nil

cancelButtonTitle:@"确定" otherButtonTitles:nil, nil nil];

[alertView show];

}

break;

default:

break;

}

}

#pragma mark mapViewDelegate

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation{

static NSString * key = @"key";

MKPinAnnotationView * pinAnnotationView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:key];

if(pinAnnotationView == nil){

pinAnnotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:key];

[pinAnnotationView setCanShowCallout:YES];

}

if([annotation isKindOfClass:[MKUserLocation class]]){

[pinAnnotationView setPinColor:MKPinAnnotationColorRed];

[((MKUserLocation *)annotation) setTitle:_titleString];

}else{

[pinAnnotationView setPinColor:MKPinAnnotationColorPurple];

}

return pinAnnotationView;

}

#pragma mark - CLLocationManangerDelegate

//定位成功以后调用

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {

[_locationManager stopUpdatingLocation];

CLLocation * location = locations.lastObject;

MKCoordinateRegion coordinateRegion = MKCoordinateRegionMake(CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude), MKCoordinateSpanMake(0.1, 0.1));

[_mapView setRegion:[_mapView regionThatFits:coordinateRegion] animated:YES];

// [self reverseGeocoder:location];

}

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

NSLog(@"error:%@",error);

}

#pragma mark Geocoder

//反地理编码

- (void)reverseGeocoder:(CLLocation *)currentLocation {

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

[geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error) {

if(error || placemarks.count == 0){

NSLog(@"error");

}else{

CLPlacemark * placemark = placemarks.firstObject;

self.titleString = placemark.name;

MKPointAnnotation * pointAnnotation = [[MKPointAnnotation alloc] init];

[pointAnnotation setTitle:placemark.name];

[pointAnnotation setCoordinate:CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude)];

[_mapView addAnnotation:pointAnnotation];

NSLog(@"placemark:%@",[[placemark addressDictionary] objectForKey:@"City"]);

}

}];

}

//地理编码

- (void)geocoder:(NSString *)str {

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

[geocoder geocodeAddressString:str completionHandler:^(NSArray *placemarks, NSError *error) {

if(error || placemarks.count == 0){

NSLog(@"error");

}else{

CLPlacemark * placemark = placemarks.firstObject;

MKCoordinateRegion coordinateRegion = MKCoordinateRegionMake(CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude), MKCoordinateSpanMake(0.1, 0.1));

[_mapView setRegion:[_mapView regionThatFits:coordinateRegion] animated:YES];

MKPointAnnotation * pointAnnotation = [[MKPointAnnotation alloc] init];

[pointAnnotation setTitle:placemark.name];

[pointAnnotation setCoordinate:CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude)];

[_mapView addAnnotation:pointAnnotation];

}

}];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

参考：http://blog.csdn.net/chenyufeng1991/article/details/48596791