iOS 大头针的基本使用

1.导入头文件

#import <MapKit/MapKit.h>

#import <CoreLocation/CoreLocation.h>

2.为成员变量mapView添加手势识别

1 - (void)viewDidLoad

2 {

3     [super viewDidLoad]; 

4     // 添加手势识别

5     [self.mapView addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapMapView:)]];

6 }

3.实现目标方法

 1 - (void)tapMapView:(UITapGestureRecognizer *)tap

 2 {

 3     // 获取所点击view的x,y坐标

 4     CGPoint point = [tap locationInView:tap.view];

 5     // x,y坐标转地理坐标

 6     CLLocationCoordinate2D coordinate = [self.mapView convertPoint:point toCoordinateFromView:tap.view];

 7     // 初始化大头针,之所以初始化大头针,是因为系统的MKAnnotation各项属性都是只读

 8     QKAnnotation *annotation = [[QKAnnotation alloc]init];

 9     // 设置大头针各项属性

10     annotation.title = @"我的大头针";

11     annotation.subtitle = @"我的大头针--子标题";

12     annotation.coordinate = coordinate;

13     // 在地图上添加大头针

14     [self.mapView addAnnotation:annotation];

15 }

3.1系统MKAnnotation各项属性,都是只读的

 1 #import <CoreGraphics/CoreGraphics.h>

 2 #import <CoreLocation/CoreLocation.h>

 3 #import <MapKit/MKFoundation.h>

 4 

 5 @protocol MKAnnotation <NSObject>

 6 

 7 // Center latitude and longitude of the annotion view.

 8 // The implementation of this property must be KVO compliant.

 9 @property (nonatomic, readonly) CLLocationCoordinate2D coordinate;

10 

11 @optional

12 

13 // Title and subtitle for use by selection UI.

14 @property (nonatomic, readonly, copy) NSString *title;

15 @property (nonatomic, readonly, copy) NSString *subtitle;

16 

17 // Called as a result of dragging an annotation view.

18 - (void)setCoordinate:(CLLocationCoordinate2D)newCoordinate NS_AVAILABLE(10_9, 4_0);

19 

20 @end

4.自定义大头针的.h文件,.m文件不需要修改

1 #import <MapKit/MapKit.h>

2 

3 @interface QKAnnotation : NSObject<MKAnnotation>

4 

5 @property (nonatomic,assign) CLLocationCoordinate2D coordinate;

6 @property (nonatomic, copy) NSString *title;

7 @property (nonatomic, copy) NSString *subtitle;

8 

9 @end

#注意:1.MKAnnotation是NSObject, 它是MKAnnotationView的一个属性

　　    2.MKAnnotationView继承自UIView

　　　 3.自定义大头针继承自NSObject. 遵守<MKAnnotation>协议,就获得了协议里申明的属性和方法.从3.1的代码可以看出,系统MKAnnotation对象,整个.h文件都是协议,coordinate是必须实现的属性,把readOnly删掉,并为coordinate属性添加assign.