使用MapKit，但默认位置是在美国加利福尼亚州。需要改成默认的

Question

使用mapkit 就可以了。用户可以移动并拖动红色图钉。但是，当我运行它时，默认位置位于 CA。当我想要它到用户当前所在的位置时。 这是代码。

#import "MapKitDragAndDropViewController.h"
#import "DDAnnotation.h"
#import "DDAnnotationView.h"


@interface MapKitDragAndDropViewController () 
- (void)coordinateChanged_:(NSNotification *)notification;
@end

@implementation MapKitDragAndDropViewController

@synthesize mapView;

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    CLLocationCoordinate2D theCoordinate;
    theCoordinate.latitude = 37.810000;
    theCoordinate.longitude = -122.477989;

    DDAnnotation *annotation = [[[DDAnnotation alloc] initWithCoordinate:theCoordinate addressDictionary:nil] autorelease];
    annotation.title = @"Drag to Move Pin";
    annotation.subtitle = [NSString stringWithFormat:@"%f %f", annotation.coordinate.latitude, annotation.coordinate.longitude];

    [self.mapView addAnnotation:annotation];    
}

- (void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

    // NOTE: This is optional, DDAnnotationCoordinateDidChangeNotification only fired in iPhone OS 3, not in iOS 4.
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(coordinateChanged_:) name:@"DDAnnotationCoordinateDidChangeNotification" object:nil];
}

- (void)viewWillDisappear:(BOOL)animated {

    [super viewWillDisappear:animated];

    // NOTE: This is optional, DDAnnotationCoordinateDidChangeNotification only fired in iPhone OS 3, not in iOS 4.
    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"DDAnnotationCoordinateDidChangeNotification" object:nil];  
}

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return YES;
}

- (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.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;

    self.mapView.delegate = nil;
    self.mapView = nil;
}

- (void)dealloc {
    mapView.delegate = nil;
    [mapView release];
    [super dealloc];
}

#pragma mark -
#pragma mark DDAnnotationCoordinateDidChangeNotification

// NOTE: DDAnnotationCoordinateDidChangeNotification won't fire in iOS 4, use -mapView:annotationView:didChangeDragState:fromOldState: instead.
- (void)coordinateChanged_:(NSNotification *)notification {

    DDAnnotation *annotation = notification.object;
    annotation.subtitle = [NSString stringWithFormat:@"%f %f", annotation.coordinate.latitude, annotation.coordinate.longitude];
}

#pragma mark -
#pragma mark MKMapViewDelegate

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)annotationView didChangeDragState:(MKAnnotationViewDragState)newState fromOldState:(MKAnnotationViewDragState)oldState {

    if (oldState == MKAnnotationViewDragStateDragging) {
        DDAnnotation *annotation = (DDAnnotation *)annotationView.annotation;
        annotation.subtitle = [NSString stringWithFormat:@"%f %f", annotation.coordinate.latitude, annotation.coordinate.longitude];        
    }
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {

    if ([annotation isKindOfClass:[MKUserLocation class]]) {
        return nil;     
    }

    static NSString * const kPinAnnotationIdentifier = @"PinIdentifier";
    MKAnnotationView *draggablePinView = [self.mapView dequeueReusableAnnotationViewWithIdentifier:kPinAnnotationIdentifier];

    if (draggablePinView) {
        draggablePinView.annotation = annotation;
    } else {
        // Use class method to create DDAnnotationView (on iOS 3) or built-in draggble MKPinAnnotationView (on iOS 4).
        draggablePinView = [DDAnnotationView annotationViewWithAnnotation:annotation reuseIdentifier:kPinAnnotationIdentifier mapView:self.mapView];

        if ([draggablePinView isKindOfClass:[DDAnnotationView class]]) {
            // draggablePinView is DDAnnotationView on iOS 3.
        } else {
            // draggablePinView instance will be built-in draggable MKPinAnnotationView when running on iOS 4.
        }
    }       

    return draggablePinView;
}

Answer 1

您需要具有类似于以下内容的代码：

    lm = [[CLLocationManager alloc] init];
    lm.delegate = self;
    lm.desiredAccuracy = kCLLocationAccuracyBest;
    [lm startUpdatingLocation];

这使用 CLLocationManager 对象来定位用户的当前位置