使用iOS中的Geocoder类，根据地址获取纬度和经度 [英] Get latitude and longitude based on Address using Geocoder class in iOS

问题描述

我根据经度和纬度值获得了当前位置，然后我还使用Annotation在Google地图上获得了多个位置。现在我想根据地址（即街道，城市和县）得到经度和纬度值。需要一些指导如何实现。

I got the current location based on the Longitude and Latitude values and then I also got multiple places on google map using Annotation. Now I want to get the longitude and latitude values based on the Address( i.e street,city and county).Need some guidance on how this can be achieved.

到目前为止，这就是我的尝试： -

Till now, this is what I have tried:-

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
@synthesize streetField = _streetField, cityField = _cityField, countryField = _countryField, fetchCoordinatesButton = _fetchCoordinatesButton, nameLabel = _nameLabel, coordinatesLabel = _coordinatesLabel;
@synthesize geocoder = _geocoder;


- (void)viewDidLoad
{

    [super viewDidLoad];
    _streetField.delegate=self;
    _cityField.delegate=self;
    _countryField.delegate=self;

    // Do any additional setup after loading the view, typically from a nib.
}

- (IBAction)fetchCoordinates:(id)sender {
    NSLog(@"Fetch Coordinates");
    if (!self.geocoder) {
          NSLog(@"Geocdoing");
        self.geocoder = [[CLGeocoder alloc] init];
    }

    NSString *address = [NSString stringWithFormat:@"%@ %@ %@", self.streetField.text, self.cityField.text, self.countryField.text];
    NSLog(@"GET Addres%@",address);

    self.fetchCoordinatesButton.enabled = NO;

    [self.geocoder geocodeAddressString:address completionHandler:^(NSArray *placemarks, NSError *error) {
          NSLog(@"Fetch Gecodingaddress");
        if ([placemarks count] > 0) {
            CLPlacemark *placemark = [placemarks objectAtIndex:0];

             NSLog(@"GET placemark%@",placemark);

            CLLocation *location = placemark.location;

            NSLog(@"GET location%@",location);

            CLLocationCoordinate2D coordinate = location.coordinate;


            self.coordinatesLabel.text = [NSString stringWithFormat:@"%f, %f", coordinate.latitude, coordinate.longitude];

            NSLog(@"CoordinatesLabel%@",self.coordinatesLabel.text);


            if ([placemark.areasOfInterest count] > 0) {
                NSString *areaOfInterest = [placemark.areasOfInterest objectAtIndex:0];
                self.nameLabel.text = areaOfInterest;
                NSLog(@"NameLabe%@",self.nameLabel.text);
            }
        }

        self.fetchCoordinatesButton.enabled = YES;
    }];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}
@end

以上代码无法给我纬度和经度。需要一些帮助，我在这里做错了什么，或者我错过了什么。

Above code is not working to give me the latitude and longitude.Need some help on what am I doing wrong here or if I am missing on something.

先谢谢。

推荐答案

编辑：

之前在iOS8更新时使用此检查

Before using this check with iOS8 updation

NSLocationAlwaysUsageDescription
NSLocationWhenInUseUsageDescription

这是为了获得基于纬度和长期的用户区域，如街道名称，州名，国家。

This is for getting lat and long based user area like street name,state name,country.

-(CLLocationCoordinate2D) getLocationFromAddressString: (NSString*) addressStr {
    double latitude = 0, longitude = 0;
    NSString *esc_addr =  [addressStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSString *req = [NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?sensor=false&address=%@", esc_addr];
    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] encoding:NSUTF8StringEncoding error:NULL];
    if (result) {
        NSScanner *scanner = [NSScanner scannerWithString:result];
        if ([scanner scanUpToString:@"\"lat\" :" intoString:nil] && [scanner scanString:@"\"lat\" :" intoString:nil]) {
            [scanner scanDouble:&latitude];
            if ([scanner scanUpToString:@"\"lng\" :" intoString:nil] && [scanner scanString:@"\"lng\" :" intoString:nil]) {
                [scanner scanDouble:&longitude];
            }
        }
    }
    CLLocationCoordinate2D center;
    center.latitude=latitude;
    center.longitude = longitude;
    NSLog(@"View Controller get Location Logitute : %f",center.latitude);
    NSLog(@"View Controller get Location Latitute : %f",center.longitude);
    return center;

}

在viewdidload方法或某处根据以下方法调用此方法你的项目

call the method like this in viewdidload method or somewhere according to your project

[self getLocationFromAddressString:@"chennai"];

只需在浏览器中传递
http://maps.google.com/maps/api/geocode/json?sensor=false&address=chennai

你将拥有lat和lon的json格式

and you will have json format with lat and lon

http://maps.google.com/maps/api/geocode/json?sensor=false&address=@"your city name here"




 NSString *address = [NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?sensor=false&address=%@ %@ %@", self.streetField.text, self.cityField.text, self.countryField.text];

此方法的使用....

the usage of this method....

CLLocationCoordinate2D center;
        center=[self getLocationFromAddressString:@"uthangarai"];
      double  latFrom=&center.latitude;
      double  lonFrom=&center.longitude;

  NSLog(@"View Controller get Location Logitute : %f",latFrom);
        NSLog(@"View Controller get Location Latitute : %f",lonFrom);

这篇关于使用iOS中的Geocoder类，根据地址获取纬度和经度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！