Question

我在下面列出了相关代码。从本质上讲，我有2个注释，我试图自定义;

annotation1我想使用图像来表示从URL接收的位置。 annotation2将由简单的引脚表示，因为它们将用于用户在app中搜索的位置，当用户按下cancel而不影响注释1时，我还需要删除注释2

基本上，我已尝试使用IF语句，但我的应用程序一直崩溃，否则它们都由annotation1的图像表示，并且在我尝试仅删除annotation2时都被删除

以下是代表ViewController.m

中注释的代码

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

@synthesize searchBar;

- (void)viewDidLoad {
    [super viewDidLoad];

    self.mapView.delegate = self;
    self.searchBar.delegate = self;

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]
                               initWithTarget:self
                               action:@selector(dismissKeyboard)];

    [self.view addGestureRecognizer:tap];

 }

- (void) dismissKeyboard
{
    [self.searchBar resignFirstResponder];
    [_mapView removeAnnotations:_mapView.annotations];
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    static NSString *identifier;
    {
        if (annotation == mapView.userLocation) return nil;

        MKAnnotationView *annotationView;
        if (annotationView == nil) {
             annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
            annotationView.enabled = YES;
            annotationView.canShowCallout = YES;
            annotationView.image = [UIImage imageNamed:@"bullet_red.png"];
        } else {
            annotationView.annotation = annotation;
        }

        return annotationView;
    }

    return nil;
}

以下是ViewController.m中的代码，它是annotation1和annotation2的源代码，它可能不相关，但以防万一

-(void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{

    CLGeocoder *geocoder = [[CLGeocoder alloc] init];
    [geocoder geocodeAddressString:self.searchBar.text completionHandler:^(NSArray *placemarks, NSError *error) {

        CLPlacemark *placemark = [placemarks objectAtIndex:0];

        MKCoordinateRegion region;
        CLLocationCoordinate2D newLocation = [placemark.location coordinate];
        region.center = [(CLCircularRegion *)placemark.region center];

        MKPointAnnotation *mapAnnotation = [[MKPointAnnotation alloc] init];
        [mapAnnotation setCoordinate:newLocation];
        [mapAnnotation setTitle:self.searchBar.text];
        [self.mapView addAnnotation:mapAnnotation];

        MKMapRect mr = [self.mapView visibleMapRect];
        MKMapPoint pt = MKMapPointForCoordinate([mapAnnotation coordinate]);
        mr.origin.x = pt.x - mr.size.width * 0.5;
        mr.origin.y = pt.y - mr.size.height *0.25;
        [self.mapView setVisibleMapRect:mr animated:YES];
    }];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSMutableArray *_locations = [[NSMutableArray alloc] init];

    NSError *error;
    NSArray *jsonArray = [NSJSONSerialization JSONObjectWithData:_downloadedData options:NSJSONReadingAllowFragments error:&error];

    CLLocationCoordinate2D coordinate;

    for (int i = 0; i < jsonArray.count; i++)
    {
        NSDictionary *jsonElement = jsonArray[i];

        MKPointAnnotation* marker = [[MKPointAnnotation alloc] init];
        coordinate.latitude = [jsonElement [@"Latitude"] doubleValue];
        coordinate.longitude = [jsonElement [@"Longitude"] doubleValue];
        marker.coordinate = coordinate;
        [_locations addObject:marker];
    }

    [self.mapView addAnnotations:_locations];
}

在同一mapview Xcode上区分2组MKAnnotations

0 个答案: