iphone - MKAnnotations 直到我滚动地图才显示

Question

好吧，我有一个带有地图的视图，我在其中加载了一些注释。一切正常，但是当我想删除这些注释并包含其他注释时，它们不会显示，直到我移动（滚动）地图。

有什么建议吗？

编辑：

似乎不是使用这个：

[self updateMap];

我必须使用：

[self performSelectorOnMainThread:@selector(updateMap) withObject:nil waitUntilDone:true];

更新映射我添加新注释的方法。

Answer 1

在 viewdidload 中使用：

- (void)viewDidLoad 

{

    NSMutableArray* annotations=[[NSMutableArray alloc] init];
    MyAnnotation* myAnnotation = [[MyAnnotation alloc] init];
myAnnotation.coordinate = theCoordinate;
    [annotations addObject:myAnnotation];
    MKMapRect flyTo = MKMapRectNull;
for (id <MKAnnotation> annotation in annotations) 
   {
    NSLog(@"fly to on");
        MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
        MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
        if (MKMapRectIsNull(flyTo)) 
        {
               flyTo = pointRect;
        }
        else
        {
               flyTo = MKMapRectUnion(flyTo, pointRect);
       //NSLog(@"else-%@",annotationPoint.x);
        }
     }

// Position the map so that all overlays and annotations are visible on screen.
mapView.visibleMapRect = flyTo;

}

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

{ NSLog(@"欢迎进入地图视图注释");

// if it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
    return nil;

// try to dequeue an existing pin view first
static NSString* AnnotationIdentifier = @"AnnotationIdentifier";
MKPinAnnotationView* pinView = [[[MKPinAnnotationView alloc]
                                 initWithAnnotation:annotation reuseIdentifier:AnnotationIdentifier] autorelease];
pinView.animatesDrop=YES;
pinView.canShowCallout=YES;
pinView.draggable = NO;
pinView.pinColor=MKPinAnnotationColorGreen;

//button on the right for popup for pins
UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[rightButton setTitle:annotation.title forState:UIControlStateNormal];
[rightButton addTarget:self
                action:@selector(showDetails:)
      forControlEvents:UIControlEventTouchUpInside];
pinView.rightCalloutAccessoryView = rightButton;

//zoom button on the left of popup for pins
UIButton* leftButton = [UIButton buttonWithType:UIButtonTypeContactAdd];
[leftButton setTitle:annotation.title forState:UIControlStateNormal];
[leftButton addTarget:self 
               action:@selector(zoomToLocation:) forControlEvents:UIControlEventTouchUpInside];
pinView.leftCalloutAccessoryView = leftButton;

UIImageView *profileIconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"profile.png"]];
pinView.leftCalloutAccessoryView = profileIconView;
[profileIconView release];


return pinView;

}

希望这会有所帮助！！！！！！！！！！

Answer 2

像这样尝试：

[mapView removeAnnotations:[mapView annotations]];
NSArray *targetArray = /*YOUR ARRAY NAME with object, containing `latitude`, `longitude` and `title` values*/
for (id *item in targetArray) {
    if (item.latitude && item.longitude) {
        MKPin *pin = [[MKPin alloc] init]; // MKPin is your class which specifies the deledate `MKAnnotation`
        pin.coordinate = CLLocationCoordinate2DMake(item.latitude, item.longitude);
        pin.title = item.title;
        [mapView addAnnotation:pin];
    }
}