Cat Learn iOS corelocation anti-geocoding small demo input latitude and longitude get the city

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Address: http://blog.csdn.net/u013357243

One: Effect

Input latitude and longitude, can get the corresponding place name

Second: Ideas

Almost identical to the field code.
1. Get the latitude and longitude of user input
2. Create a Cllocation object based on the latitude and longitude of the user input
3. Get the relevant landmark information based on the Cllocation object

Three: Code

#import "ViewController.h" #import <CoreLocation/CoreLocation.h>  @interface viewcontroller ()/** * GeoCode objects * /@property(nonatomic,Strong) Clgeocoder *geocoder;#pragma mark-anti-geocoding- (ibaction) Reversegeocode;@property(Weak,nonatomic)IboutletUitextfield *longtitudefield;@property(Weak,nonatomic)IboutletUitextfield *latitudefield;@property(Weak,nonatomic)Iboutlet UILabel*reversedetailaddresslabel;@end @implementation viewcontroller - (void) reversegeocode{//1. Get the latitude and longitude of user input    NSString*longtitude = Self. Longtitudefield. Text;NSString*latitude = Self. Latitudefield. Text;if(Longtitude. Length==0|| Longtitude = =Nil|| Latitude. Length==0|| Latitude = =Nil) {NSLog(@"Please enter latitude and longitude");return; }//2. Create a Cllocation object based on the latitude and longitude of user inputCllocation *location = [[Cllocation alloc] initwithlatitude:[latitude Doublevalue] Longitude:[longtitude DoubleValue] ;//3. Get the relevant landmark information based on the Cllocation object[ Self. GeocoderReversegeocodelocation:location completionhandler:^ (Nsarray*placemarks,Nserror*error) { for(Clplacemark *placemark in Placemarks) {NSLog(@"%@%@%f%f", Placemark. Name, Placemark. Addressdictionary, Placemark. location. Coordinate. Latitude, Placemark. location. Coordinate. Longitude); Self. Reversedetailaddresslabel. Text= Placemark. Locality; }    }];}#pragma mark-Lazy loading-(Clgeocoder *) geocoder{if(!_geocoder)    {_geocoder = [[Clgeocoder alloc] init]; }return_geocoder;}@end

Four: Knowledge expansion Clgeocoder

"Geocoding" and "anti-geocoding" can be completed using Clgeocoder
Geocoding: Based on a given place name. Get detailed location information (such as latitude and longitude, full name of address, etc.)
Anti-geocoding: Get detailed location information based on a given latitude and longitude

Geography Coding Method

- (void)geocodeAddressString:(NSString *)addressString completionHandler:(CLGeocodeCompletionHandler)completionHandler;

--Anti-geo-coding method

- (void)reverseGeocodeLocation:(CLLocation *)location completionHandler:(CLGeocodeCompletionHandler)completionHandler;

Clgeocodecompletionhandler

When Geo-geocoding is complete, it calls the

typedefvoid (^CLGeocodeCompletionHandler)(NSArrayNSError *error);

This block transmits 2 parameters
Error: There is a value when the coding error (for example, the code does not have detailed information)
Placemarks: It contains Clplacemark objects.

Clplacemark

Clplacemark literally means a landmark, encapsulating detailed address location information

Location

@property (nonatomicreadonly) CLLocation *location;

Regional

@property (nonatomicreadonly) CLRegion *region;

Detailed address information

@property (nonatomicreadonlyNSDictionary *addressDictionary;

Address name

@property (nonatomicreadonlyNSString *name;

City

@property (nonatomicreadonlyNSString *locality;

Structure diagram

Cat Learn iOS corelocation anti-geocoding small demo input latitude and longitude get the city