- (MKAnnotationView *)mapView 没有被调用

Question

在我的代码中， - (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id)annotation 方法没有被调用。我不知道为什么。有人可以帮我吗？

下面是我的代码：

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

    MKPinAnnotationView *pinView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@","];
    NSLog(@"pin map");
    if(pinView == nil) 
    {
        pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@""];

        pinView.animatesDrop = YES;
        pinView.canShowCallout = YES;

        UIImage *image = [UIImage imageNamed:@"ann.png"];

        CGRect resizeRect;

        resizeRect.size = image.size;
        CGSize maxSize = CGRectInset(self.view.bounds,
                                     [map annotationPadding],
                                     [map annotationPadding]).size;*/
        maxSize.height -= self.navigationController.navigationBar.frame.size.height + [map calloutHeight];
        if (resizeRect.size.width > maxSize.width)
            resizeRect.size = CGSizeMake(maxSize.width, resizeRect.size.height / resizeRect.size.width * maxSize.width);
        if (resizeRect.size.height > maxSize.height)
            resizeRect.size = CGSizeMake(resizeRect.size.width / resizeRect.size.height * maxSize.height, maxSize.height);

        resizeRect.origin = (CGPoint){0.0f, 0.0f};

        UIGraphicsBeginImageContext(resizeRect.size);
        [image drawInRect:resizeRect];
        UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        pinView.image = resizedImage;
        pinView.opaque = NO;

        UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        [rightButton addTarget:self
                        action:@selector(showDetails:)
              forControlEvents:UIControlEventTouchUpInside];
        pinView.rightCalloutAccessoryView = rightButton;

        if (annotation == mapView.userLocation)
        {

            return nil;
        }
        return pinView;

    } 
    else 
    {

        pinView.annotation = annotation;
    }

    return pinView;

}

这就是我向地图添加注释的方式：

-(void) Annotations:(int)i
{

    /*NSString* address = [mpartyDetail objectAtIndex:i];
    address = [[address componentsSeparatedByCharactersInSet: [NSCharacterSet whitespaceCharacterSet]] componentsJoinedByString: @""];
    NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%@&output=csv", address];
    NSLog(@"nsstring %@",urlString);
    NSString *locationString = [[[NSString alloc] initWithContentsOfURL:[NSURL URLWithString:urlString]] autorelease];
    NSLog(@"location string %@",locationString);
    NSArray *latlng = [locationString componentsSeparatedByString:@","];
    NSLog(@"the latlng %@",latlng);

    float lat = [[latlng objectAtIndex:2] floatValue];
    float lng = [[latlng objectAtIndex:3] floatValue]; */
    NSLog(@"ann");
    lat = [[latiArray objectAtIndex:i]floatValue];
    lng = [[longiArray objectAtIndex:i]floatValue]; 
    CLLocationCoordinate2D newCoord = {lat,lng};
    mapAnnotations* annotation = [[mapAnnotations alloc] initWithCoordinate:newCoord];

    [mapView addAnnotation:annotation];

}

mapAnnotations 是另一个类。下面的代码显示了被调用的该类的方法：

- (id)initWithCoordinate:(CLLocationCoordinate2D)coordinate{

    NSLog(@"the cor");
    self = [super init];

    if (self != nil) {
        NSLog(@"in");
        _coordinate = coordinate;

    }

    return self;

}

这个想法是，当用户按下地图时我添加注释，并且用户可以为该图钉提供任何标题。我需要一个标注来显示用户输入的标题。正在添加注释。但我无法获得标注，因为没有调用此方法。

Answer 1

您是否将包含该方法的类指定为地图视图的委托，是否实际上向地图视图添加了任何注释，以及这些注释的位置在当前显示在屏幕上的地图部分中是否实际可见？

Answer 2

正如有人正确指出的那样，在我的例子中，代表没有设置为同一类别
我所做的只是在代码中添加注释，我编写了代码：

mapView.delegate=self;

它对我来说非常有用。
如果你没有这样做，那就去做吧，它可能对你也有用。

Answer 3

您如何向地图添加注释？我用以下

while(some condition){
MapAnnotation *annotation = [[MapAnnotation alloc] initWithLatitude:(float)goLat Longitude:(float)goLng title:(NSString*)recallTask.blurb subtitle:(NSString*)recallTask.location];
        [appDelegate.annArray addObject:annotation];
        [annotation release];
        annotation = nil;
    }
[self.mapView addAnnotations:appDelegate.annArray];