iOS 根据经纬度显示地图位置

好久没写了，赶项目你懂得。
直接上图吧，╮(╯▽╰)╭。

需求！！！

#import <UIKit/UIKit.h>

 @interface SearchViewController : UIViewController
//纬度
@property (nonatomic, copy) NSString *latitude;    NSString * latitu

@property nonatomic copy NSSstring
//经度
@property (nonatomic, copy) NSString *longitude;
//地名
@property (nonatomic, copy) NSString *addressName;
@end

  //
 //  SearchViewController.m
 //  CircleFace
 //  Created by chylee on 16/5/17.
 //  Copyright © 2016年 . All rights reserved.


#import "SearchViewController.h"
#import <MapKit/MapKit.h>
#import "MapAnnotation.h"
@interface SearchViewController ()<MKMapViewDelegate>{
    MKMapView *mapView;
}

@end

@implementation SearchViewController

- (void)viewDidLoad {
     [super viewDidLoad];

     self.navigationItem.leftBarButtonItem = [UIBarButtonItem createBarButtonItemWithTitle:nil imageName:@"返回白色" highlightedImageName:@"返回白色" target:self selector:@selector(back) font:0];
      mapView = [[MKMapView alloc]initWithFrame:self.view.bounds];
      [self.view addSubview:mapView];
   // 设置代理
       mapView.delegate = self;

       CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake([_latitude doubleValue],[_longitude doubleValue]);
       MapAnnotation *annotation = [[MapAnnotation alloc] init];
       annotation.coordinate = coordinate;
       annotation.title = _addressName;
       [mapView addAnnotation:annotation];
       [mapView setRegion:MKCoordinateRegionMakeWithDistance(coordinate, 2000, 2000)];
}

    - (MKAnnotationView *)mapView:(MKMapView *)mapView     viewForAnnotation:(id<MKAnnotation>)annotation
{
      MKPinAnnotationView *annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"MapSample"];
      annotationView.canShowCallout = YES;
     return annotationView;
}

- (void)back {
      [self.navigationController popViewControllerAnimated:YES];
}

  @end

因为需要在地图上显示经纬度对应位置，使用了MapAnnotation，新建一个annotion类，继承NSObject，为这个类设置两个属性，CLLocationCoordinate2D、title.

  //
  //  MapAnnotation.h
  //  CircleFace
  //
  //  Created by chylee on 16/5/17.
  //  Copyright © 2016年 . All rights reserved.
  //

   #import <Foundation/Foundation.h>
   #import <MapKit/MapKit.h>

  @interface MapAnnotation : NSObject <MKAnnotation>

  @property (nonatomic) CLLocationCoordinate2D coordinate;

  @property (nonatomic, copy) NSString *title;

  @end