当我使用此代码尝试从 MySQL 数据库调用 Lat & Long 坐标（并将它们显示在 MapView 上）时，应用程序运行良好。一切似乎都正常，但由于某种原因，xcode 在地图加载之前暂停了模拟器，并向我抛出了一个 SIGABRT。知道为什么吗？见下文：
MapViewController.h
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
@interface MapViewController : UIViewController <MKMapViewDelegate>
@property (nonatomic, strong) IBOutlet MKMapView *mapView;
@property (nonatomic, retain) NSMutableArray *dispensaries;
@property (nonatomic, retain) NSMutableData *data;
@end
MapViewController.m
#import "MapViewController.h"
#import "MapViewAnnotation.h"
@implementation MapViewController
@synthesize mapView;
@synthesize dispensaries;
@synthesize data;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad {
[super viewDidUnload];
NSLog(@"Getting Device Locations");
NSString *hostStr = @"http://stylerepublicmagazine.com/dispensaries.php";
NSData *dataURL = [NSData dataWithContentsOfURL:[NSURL URLWithString:hostStr]];
NSString *serverOutput = [[NSString alloc] initWithData:dataURL encoding: NSASCIIStringEncoding];
NSLog(@"server output: %@", serverOutput);
NSMutableArray *array = (NSMutableArray *)dispensaries;
dispensaries = [NSJSONSerialization JSONObjectWithData:data options:nil error:nil];
for (NSDictionary *dictionary in array) {
CLLocationCoordinate2D coord = {[[dictionary objectForKey:@"lat"] doubleValue], [[dictionary objectForKey:@"lng"] doubleValue]};
MapViewAnnotation *ann = [[MapViewAnnotation alloc] init];
ann.title = [dictionary objectForKey:@"Name"];
ann.coordinate = coord;
[mapView addAnnotation:ann];
[mapView setMapType:MKMapTypeStandard];
[mapView setZoomEnabled:YES];
[mapView setScrollEnabled:YES];
self.mapView.delegate = self;
}
}
- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(userLocation.coordinate, 800, 800);
[self.mapView setRegion:[self.mapView regionThatFits:region] animated:YES];
MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
point.coordinate = userLocation.coordinate;
point.title = @"You Are Here";
point.subtitle = @"Your current location";
[self.mapView addAnnotation:point];
}