Question

努力寻找一种方法，使地图缩放并以注释引脚为中心。 Pin下降，但地图加载海洋。代码如下。

- (void) connectionDidFinishLoading:(NSURLConnection *)connection
{
  [self setString];

  NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:nil];
  NSDictionary *location = [dic objectForKey:@"location"];
  NSDictionary *coordinate = [location objectForKey:@"coordinate"];
  NSString *lat = [coordinate objectForKey:@"latitude"];
  NSString *lon = [coordinate objectForKey:@"longitude"];

  for (NSDictionary *diction in coordinate)
  {
    [array addObject:lat];
    [array addObject:lon];
  }
  {
    CLLocationCoordinate2D track;
    track.latitude = [lat doubleValue];
    track.longitude = [lon doubleValue];

    MapViewAnnotation *newAnnotation = [[MapViewAnnotation alloc] initWithTitle:@"Title of Place Here" andCoordinate:track];

    [self.mapView addAnnotation:newAnnotation];
  }
}

第二个问题，非常相关：

在实现上述问题的答案后，我已经修改了我的代码。现在，我的坐标从前一个视图到我的MKMapView，所以我不必费心去做两次API调用，第二个是在MKMapView中。目前在我的ViewWillAppear中，我有以下内容，并且AGAIN遇到了一个问题，即视图不会居中并放大针脚：

if ([self.stringToDisplay isEqualToString: @"Firehouse Gallery"])
{
    UIImage *img = [UIImage imageNamed:@"firehouse.jpg"];
    [imageView setImage:img];

    CLLocationCoordinate2D track;
    track.latitude = [lat doubleValue];
    track.longitude = [lon doubleValue];

    MKCoordinateRegion region;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.01;
    span.longitudeDelta = 0.01;
    region.span = span;
    region.center = track;

    MapViewAnnotation *newAnnotation = [[MapViewAnnotation alloc] initWithTitle:@"Firehouse Gallery" andCoordinate:track];

    [self.mapView addAnnotation:newAnnotation];
    [self.mapView setRegion:region animated:TRUE];
    [self.mapView regionThatFits:region];
}

非常感谢您的反馈，因为我无法分辨我还应该做些什么。引脚加载在正确的坐标上，只是没有居中/缩放......

Answer 1

试试这个：

{
    CLLocationCoordinate2D track;
    track.latitude = [lat doubleValue];
    track.longitude = [lon doubleValue];

    MKCoordinateRegion region;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.01;
    span.longitudeDelta = 0.01;
    region.span = span;
    region.center = track;

    MapViewAnnotation *newAnnotation = [[MapViewAnnotation alloc] initWithTitle:@"Title of Place Here" andCoordinate:track];

    [self.mapView addAnnotation:newAnnotation];
    [self.mapView setRegion:region animated:TRUE];
    [self.mapView regionThatFits:region];
}

Answer 2

 - (void)zoomMapViewToFitAnnotationsWithExtraZoomToAdjust:(double)extraZoom
 {
    if ([self.annotations count] == 0) return;

    int i = 0;
    MKMapPoint points[[self.annotations count]];

    for (id<MKAnnotation> annotation in [self annotations])
    {
        points[i++] = MKMapPointForCoordinate(annotation.coordinate);
    }

    MKPolygon *poly = [MKPolygon polygonWithPoints:points count:i];

    MKCoordinateRegion r = MKCoordinateRegionForMapRect([poly boundingMapRect]);
    r.span.latitudeDelta += extraZoom;
    r.span.longitudeDelta += extraZoom;

    [self setRegion: r animated:YES];
 }

试图在Pin上居中地图（MKMapView）

2 个答案: