ios - Mapkit map View 在第一次尝试时未显示

Question

我在 RootViewController.m 上有一个选项卡。该选项卡有 2 个按钮。单击第一个按钮将转到上面有 mapView 的 CorpViewcontroller。当我第一次尝试点击第一个按钮时， map 是空白的，底部有谷歌标签。我必须单击返回然后再次单击按钮然后 map 显示。是否可以始终在第一次单击按钮时显示 map ？

我的 rootViewController.m 转到第二个屏幕:

  [self.navigationController pushViewController:self.corpController animated:YES];

名为 corpViewController 的第二个屏幕具有以下代码:

  - (void)viewDidLoad
  {
    [super viewDidLoad];

    self.title = @"Set Remote Location";
    self.jsonData = [[NSMutableData alloc] init];

    mapView.showsUserLocation = YES;

    //Setup the double tap gesture for getting the remote location..
    UITapGestureRecognizer *tgr = [[UITapGestureRecognizer alloc] 
                               initWithTarget:self action:@selector(handleGesture:)];
    tgr.numberOfTapsRequired = 2;
    tgr.numberOfTouchesRequired = 1;
    [mapView addGestureRecognizer:tgr];

    mapView.delegate = self;

    NSLog(@"viewDidLoad  done");
    }


    - (void)viewWillAppear:(BOOL)animated    {

      NSLog(@"viewWillAppear");

      appDelegate = (NBSAppDelegate *)[[UIApplication sharedApplication] delegate];

      double curLat = [appDelegate.curLat doubleValue];

      MKUserLocation *userLocation = mapView.userLocation;

      double miles = 10.0;
      double scalingFactor = ABS( (cos(2 * M_PI * curLat / 360.0) ));

      MKCoordinateSpan span; 

      span.latitudeDelta = miles/69.0;
      span.longitudeDelta = miles/(scalingFactor * 69.0); 

      MKCoordinateRegion region2;
      region2.span = span;
      region2.center = userLocation.coordinate;

      [mapView setRegion:region2 animated:YES];

       NSLog(@"viewWillAppear done..");

       }

请指教。

谢谢

Answer 1

您是否在 View Controller 的 viewDidLoad 方法中初始化 MapView？

如果是这样，请尝试将其移至 viewDidAppear 方法。这对我有用。