Oc 地图覆盖层

实现代码

#import <MapKit/MapKit.h>#import "FKViewController.h"@interface FKViewController () <MKMapViewDelegate>@property (nonatomic, strong) MKMapView* mapView;@end@implementation FKViewController- (void)viewDidLoad{    [super viewDidLoad];    self.mapView = [[MKMapView alloc] initWithFrame:self.view.bounds];    self.mapView.zoomEnabled = YES;    // 设置地图可滚动    self.mapView.scrollEnabled = YES;    // 设置地图不可旋转    self.mapView.rotateEnabled = NO;    // 设置地图显示用户位置    self.mapView.showsUserLocation = YES;    [self.view addSubview:self.mapView];    [self locateToLatitude:23.126272 longitude:113.395568];    // 创建一个手势处理器，用于检测、处理长按手势    UILongPressGestureRecognizer* gesture = [[UILongPressGestureRecognizer        alloc]initWithTarget:self action:@selector(longPress:)];    [self.mapView addGestureRecognizer:gesture];    self.mapView.delegate = self;}- (void)locateToLatitude:(CGFloat)latitude longitude:(CGFloat)longitude{    // 设置地图中心的经、纬度    CLLocationCoordinate2D center = {latitude , longitude};    // 设置地图显示的范围，    MKCoordinateSpan span;    // 地图显示范围越小，细节越清楚    span.latitudeDelta = 0.01;    span.longitudeDelta = 0.01;    // 创建MKCoordinateRegion对象，该对象代表了地图的显示中心和显示范围。    MKCoordinateRegion region = {center,span};    // 设置当前地图的显示中心和显示范围    [self.mapView setRegion:region animated:YES];}- (void) longPress:(UILongPressGestureRecognizer*)gesture{    // 获取长按点的坐标    CGPoint pos = [gesture locationInView:self.mapView];    // 将长按点的坐标转换为经度、维度值    CLLocationCoordinate2D coord = [self.mapView convertPoint:pos        toCoordinateFromView:self.mapView];    // 创建MKCircle对象，该对象代表覆盖层    MKCircle* circle = [MKCircle circleWithCenterCoordinate:coord radius:100];    // 添加MKOverlay    [self.mapView addOverlay:circle level:MKOverlayLevelAboveLabels];}// MKMapViewDelegate协议中的方法，该方法返回的MKOverlayRenderer负责绘制覆盖层控件- (MKOverlayRenderer *)mapView:(MKMapView *)mapView    rendererForOverlay:(id<MKOverlay>)overlay{    MKCircle * circle = (MKCircle*)overlay;    // 创建一个MKCircleRenderer对象    MKCircleRenderer* render = [[MKCircleRenderer alloc] initWithCircle:circle];    // 设置MKCircleRenderer的透明度    render.alpha = 0.5;    // 设置MKCircleRenderer的填充颜色和边框颜色    render.fillColor = [UIColor blueColor];    render.strokeColor = [UIColor redColor];    return render;}@end