IOS Development Offline Map core code _ios

One, the effect chart.

Second, engineering drawings.

Three, code.

ViewController.h

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import "MapLocation.h"
@ Interface Viewcontroller:uiviewcontroller
<MKMapViewDelegate>
{
  mkmapview *_mapview;
  NSString *addressstring;
}

Viewcontroller.m

 #import "ViewController.h" @interface Viewcontroller () @end @implementation Viewcontroller-(void) Viewdidload {[sup
  ER viewdidload];
  Do no additional setup after loading the view.
  Call the system's own gold map//show the current location of the offline map _mapview = [[Mkmapview alloc] init];
  _mapview.frame = CGRectMake (0, 40, 320,400);
  _mapview.delegate = self;
  _mapview.maptype = Mkmaptypestandard;
  [Self.view Addsubview:_mapview];
  addressstring=@ "Light Kai City";
  NSLog (@ "---addressstring---%@", addressstring);
[Self geocodequery]; }-(void) geocodequery{if (addressstring = = Nil | |
  [addressstring length] = = 0) {return;
  } clgeocoder *geocoder = [[Clgeocoder alloc] init]; [Geocoder geocodeaddressstring:addressstring completionhandler:^ (Nsarray *placemarks, NSError *error)
    {NSLog (@ "Query records:%ld", [Placemarks Count]);
    if ([placemarks count] > 0) {[_mapview removeannotations:_mapview.annotations]; for (int i = 0; i < [Placemarks count]; i++) {clplacemark* placemark = plaCemarks[i]; Adjust map position and zoom ratio mkcoordinateregion viewregion = mkcoordinateregionmakewithdistance (placemark.location.coordinate, 100
      00, 10000);
      [_mapview setregion:viewregion Animated:yes];
      MapLocation *annotation = [[MapLocation alloc] init];
      annotation.streetaddress = Placemark.thoroughfare;
      annotation.city = placemark.locality;
      Annotation.state = Placemark.administrativearea;
      Annotation.zip = Placemark.postalcode;
      Annotation.coordinate = placemark.location.coordinate;
    [_mapview addannotation:annotation];
}
  }]; #pragma mark Map View Delegate Methods-(Mkannotationview *) Mapview: (Mkmapview *) Themapview viewforannotation: (ID < mkannotation>) Annotation {Mkpinannotationview *annotationview = (Mkpinannotationview *) [_mapview DequeueReusableA
  nnotationviewwithidentifier:@ "Pin_annotation"];
                  if (Annotationview = = nil) {Annotationview = [[Mkpinannotationview alloc] Initwithannotation:annotation           reuseidentifier:@ "Pin_annotation"];
  } Annotationview.pincolor = Mkpinannotationcolorpurple;
  Annotationview.animatesdrop = YES;
  Annotationview.canshowcallout = YES;
return annotationview; }-(void) Mapview: (Mkmapview *) Mapview didupdateuserlocation: (mkuserlocation *) Userlocation {_
Mapview.centercoordinate = userLocation.location.coordinate; }-(void) Mapviewdidfailloadingmap: (Mkmapview *) Themapview witherror: (nserror *) error {NSLog (@ "error:%@", [Error DESCR
Iption]);  } @end

MapLocation.h

#import <MapKit/MapKit.h>
@interface maplocation:nsobject<mkannotation>
//Street Info Properties
@ Property (nonatomic, copy) NSString *streetaddress;
City Information attribute
@property (nonatomic, copy) NSString *city;
State, provincial and municipal information
@property (nonatomic, copy) NSString *state;
Zip code
@property (nonatomic, copy) NSString *zip;
Geographical coordinates
@property (nonatomic, ReadWrite) cllocationcoordinate2d coordinate;

Maplocation.m

Map Call function
#import "MapLocation.h"
@implementation maplocation
-(NSString *) title {return
  @ "your location!";
}
-(NSString *) subtitle {
  nsmutablestring *ret = [nsmutablestring new];
  if (_state)
    [ret appendstring:_state];
  if (_city)
    [ret appendstring:_city];
  if (_city && _state)
    [ret appendstring:@ ","];
  if (_streetaddress && (_city | | _state | | _zip))
    [ret appendstring:@ "·"];
  if (_streetaddress)
    [ret appendstring:_streetaddress];
  if (_zip)
    [ret appendformat:@ ",%@", _zip];
  return ret;
}
@end