iOS：实现MKAnnotation协议,在地图上设置大头针,点击显示具体的位置信息

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

@interface MyAnnotation : NSObject<MKAnnotation>
@property (assign,nonatomic)CLLocationCoordinate2D coordinate;   //经纬度坐标
@property (copy,nonatomic)NSString *title; //大头针标注标题
@property (copy,nonatomic)NSString *subtitle; //大头针标注子标题
@end

#import "ViewController.h"
#import <MapKit/MapKit.h>
#import "MyAnnotation.h"

@interface ViewController ()<MKMapViewDelegate>
@property (strong,nonatomic)MKMapView *mapView;  //声明地图视图控件
@end

- (void)viewDidLoad {
    [super viewDidLoad];
    //创建Map实例
    self.mapView = [[MKMapView alloc]initWithFrame:self.view.frame];
    
    //设置地图的类型
    self.mapView.mapType =  MKMapTypeStandard;
    
    //设置地图的代理
    self.mapView.delegate = self;
    
    //将地图视图添加到控制器视图中
    [self.view addSubview:self.mapView];
    
    //创建一个标注
    MyAnnotation *annotation = [[MyAnnotation alloc]init];
    
    //设置北京的经纬度
    annotation.coordinate = CLLocationCoordinate2DMake(40, 110);
    annotation.title = @"中国";
    annotation.subtitle = @"北京";
    
    //添加标注
    [self.mapView addAnnotation:annotation];
    
    
    //让地图显示标注的区域
    [self.mapView setCenterCoordinate:annotation.coordinate animated:YES];
    
    
    //添加一个长按longPress手势
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPress:)];
    [self.mapView addGestureRecognizer:longPress];
}

-(void)longPress:(UILongPressGestureRecognizer *)sender
{
    //获取当前位置
    CGPoint location = [sender locationInView:self.view];
    
    //经纬度
    CLLocationCoordinate2D coordinate = [self.mapView convertPoint:location toCoordinateFromView:self.mapView];
    
    
    //创建新的标注
    MyAnnotation *annotation = [[MyAnnotation alloc]init];
    annotation.coordinate = coordinate;
    annotation.title = @"新标注";
    annotation.subtitle = @"待开发...";
    
    
    //添加标注
    [self.mapView addAnnotation:annotation];
}

#pragma mark 显示标注视图
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    //设置重用标示符
    static NSString *annotationID = @"annotation";
    
    //先从重用的队列中找
    MKPinAnnotationView *view = (MKPinAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:annotationID];
    
    //没找到就创建
    if (!view)
    {
        view = [[MKPinAnnotationView alloc]init];
    }
    
    //设置属性
    view.annotation = annotation;
    view.canShowCallout = YES;//显示气泡
    view.pinColor = MKPinAnnotationColorGreen;//大头针颜色
    
    //显示图片,取代大头针
    //view.image = [UIImage imageNamed:@"1.png"];
    
    //在气泡视图中显示图片
    view.rightCalloutAccessoryView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"1.png"]];
    
    return view;
}

#pragma mark 选中了标注的处理事件
-(void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view
{
    NSLog(@"选中了标注");
}

#pragma mark 取消选中标注的处理事件
-(void)mapView:(MKMapView *)mapView didDeselectAnnotationView:(MKAnnotationView *)view
{
    NSLog(@"取消了标注");
}