Question

我正在构建一个使用Mapkit的OSX应用程序，当我点击地图上的MKAnnotationView时，我正试图显示一个标注。为此，我正在实现MKMapViewDelegate，以及以下函数：

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[LocationPin class]]) {
    LocationPin *returnPin = (LocationPin *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"LocationPin"];
    if (!returnPin){
        returnPin = [LocationPin createLocationPinForMapView:mapView annotation:annotation];
    }
    returnPin.title = annotation.title;
    NSButton *rightButton = [[NSButton alloc] initWithFrame:NSMakeRect(0.0, 0.0, 100.0, 80.0)];
    [rightButton setTitle:@"Info"];
    [rightButton setBezelStyle:NSShadowlessSquareBezelStyle];
    returnPin.annotation = annotation;
    returnPin.canShowCallout = YES;
    returnPin.rightCalloutAccessoryView = rightButton;
    return returnPin;
    }
    return nil;
    }

每次我放下一个新引脚时，该函数运行正常，我确保引脚的标题不为空或为空，但标注仍未显示。有人有什么想法吗？

编辑：在查看了Anna的回复之后，我意识到我误解了如何实现MKAnnotation协议。我已经删除了继承自MKAnnotationView的LocationPin类，而是添加了以下类来表示我的自定义MKAnnotation，其中包含一个类来生成自定义MKAnnotationView：

@implementation LocationAnnotation:

-(id)initWithTitle:(NSString *)newTitle Location:(CLLocationCoordinate2D)location     {
    self = [super init];

    if(self) {
    _title = newTitle;
    _coordinate = location;
    }

    return self;
}

- (MKAnnotationView *)annotationView {

    MKAnnotationView *annotationView = [[MKAnnotationView alloc]initWithAnnotation:self reuseIdentifier:@"LocAnno"];
    annotationView.enabled = YES;
    annotationView.canShowCallout = YES;
    annotationView.image = [NSImage imageNamed:@"dvd"];

    NSButton *rightButton = [[NSButton alloc] initWithFrame:NSMakeRect(0.0, 0.0, 100.0, 80.0)];
    [rightButton setTitle:@"Info"];
    [rightButton setBezelStyle:NSShadowlessSquareBezelStyle];

    annotationView.rightCalloutAccessoryView = rightButton;

    return annotationView;
}

@end

我现在也改变了MKMapViewDelegate功能：

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
    if ([annotation isKindOfClass:[LocationAnnotation class]]) {

        LocationAnnotation *anno = (LocationAnnotation *)annotation;
        MKAnnotationView *returnPin = [mapView dequeueReusableAnnotationViewWithIdentifier:@"LocAnno"];
        if (!returnPin){
            returnPin = anno.annotationView;
        }
        else {
            returnPin.annotation = annotation;
        }
        return returnPin;
    }
    return nil;
}

但是标注仍然没有出现。任何帮助表示赞赏。

编辑2：根据要求，LocationAnnotation.h：

#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>
@interface LocationAnnotation : NSObject <MKAnnotation>

@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
@property (copy, nonatomic) NSString *title;

-(id)initWithTitle:(NSString *)newTitle Location:(CLLocationCoordinate2D)location;
-(MKAnnotationView *)annotationView;



@end

Answer 1

我弄清楚出了什么问题。我是MKMapView的子类，显然不是Apple推荐的，因为它可能会导致一些不必要的行为。

无法显示自定义MKAnnotationView标注

1 个答案: