Question

我正处于iOS编程第5章的开头：大书呆子牧场指南（第3版）。我似乎遇到的问题是蓝点（用户）没有开始显示，不仅我的地图似乎也没有显示。我在XIB文件中的连接似乎是正确的，但我对这个问题感到茫然，有人可以提供帮助。感谢。

import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>

@interface WhereamiViewController : UIViewController <CLLocationManagerDelegate,MKMapViewDelegate>
{
   CLLocationManager *locationManager;

   IBOutlet MKMapView *worldView;

   IBOutlet UIActivityIndicatorView *activityIndicator;
   IBOutlet UITextField *locationTitleField;
}
@end




#import "WhereamiViewController.h"

@interface WhereamiViewController ()


@end

@implementation WhereamiViewController
-(id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

if (self) {
    // Create location manger object
    locationManager = [[CLLocationManager alloc] init];

    // There will be a warning from this line of code; ignore it for now
    [locationManager setDelegate:self];

    // And we want it to be as accurate as possible
    // regardless of how much time/power it takes
    [locationManager setDesiredAccuracy:kCLLocationAccuracyBest];

    // Don't need this line as it is implemented in MKMapView
    //[locationManager startUpdatingLocation];          
   }
   return self;
}

-(void) viewDidLoad
{
NSLog(@"world view:set show user locatio");
 NSLog(@"%@", worldView);
[worldView setShowsUserLocation:YES];
}

-(void) locationManager: (CLLocationManager *) manager
didUpdateToLocation:(CLLocation *)newLocation 
       fromLocation:(CLLocation *)oldLocation
{
   NSLog(@"%@", newLocation);
}
-(void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
   CLLocationCoordinate2D loc = [userLocation coordinate];
   MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(loc, 250, 250);

   [worldView setRegion:region animated:YES];

}
-(void) locationManger:(CLLocationManager *)manager
     didFailWithError: (NSError *) error
{
 NSLog(@"Could not find location: %@", error);
}

-(void)dealloc
{
//Tell the location manager to stop sending us message
  [locationManager setDelegate:nil];
}
@end

此外，显示您分配+ init WhereamiViewController的代码。

#import <UIKit/UIKit.h>

@class WhereamiViewController;
@interface WhereamiAppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) WhereamiViewController *viewController;

@end


#import "WhereamiAppDelegate.h"
#import "WhereamiViewController.h"

@implementation WhereamiAppDelegate
@synthesize window = _window;
@synthesize viewController = _viewController;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
{
  self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
  // Override point for customization after application launch.
  self.viewController = [[WhereamiViewController alloc] initWithNibName:@"WhereamiViewController" bundle:nil];
  self.window.rootViewController = self.viewController;
  [self.window makeKeyAndVisible];
  return YES;
}
@end

请参阅注释部分，了解IBOutlet MKMapView * worldView的调试器输出。

XCode中不显示地图和蓝点

0 个答案: