Question

我的MKPointAnnotation应该使用此代码进行自定义：

-(MKPointAnnotation*)setAnnotation: (NSString*) title atLocation:(CLLocationCoordinate2D)Location withImage:(UIImage*) LocationImage{
    Pin = [[MKPointAnnotation alloc] init];
    Pin.title = title;
    [Pin setCoordinate:Location];
    [self mapView:mapView viewForAnnotation:Pin].annotation = Pin;
    return Pin;
}



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

        MKPinAnnotationView* pinView = (MKPinAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:@"CustomPinAnnotationView"];


        if(!pinView){
            pinView = [[MKPinAnnotationView alloc]initWithAnnotation:annotation reuseIdentifier:@"CustomPinAnnotationView"];
            pinView.animatesDrop = YES;
            pinView.canShowCallout = YES;
            pinView.enabled = YES;
            UIButton *PicButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
            [PicButton addTarget:self action:@selector(showLocationPicture) forControlEvents:UIControlEventTouchUpInside];\
            pinView.rightCalloutAccessoryView = PicButton;
        }
        else{
            pinView.annotation = annotation;
        }
    return pinView;
}

然而，出于某种原因，Pin仍然是默认的，任何人都可以帮助我吗？感谢

Answer 1

您不应该自己致电viewForAnnotation。您只应在地图视图中添加注释，然后确定在任何给定时刻可见的注释，并为您调用viewForAnnotation。因此：

鉴于不同的注释可以有不同的图像，你真的想要子类MKPointAnnotation并给它一个imageName的属性（注意，而不是UIImage本身，但是viewForAnnotation可用于创建UIImage本身的名称或标识符：
```
@interface MyAnnotation : MKPointAnnotation
@property(nonatomic, strong) NSString *imageName;
@end

@implementation MyAnnotation
@end
```

向地图视图添加注释（不是注释视图），例如：

- (id<annotation>)addAnnotationWithTitle:(NSString *)title coordinate:(CLLocationCoordinate2D)coordinate imageName:(NSString *)imageName
{
    MyAnnotation *annotation = [[MyAnnotation alloc] init];
    annotation.title = title;
    annotation.coordinate = coordinate;
    annotation.imageName = imageName;
    [mapView addAnnotation:annotation];
    return annotation;
}

注意，我不建议将Pin作为类ivar / property，并且我将camelCase用于变量名（以小写开头），我将从setAnnotation更改方法名称类似于addAnnotationWithTitle等

确保您的控制器已被指定为mapView的委托;

将为您调用viewForAnnotation（如果注释可见）。它可能应该是这样的：

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

    if ([annotation isKindOfClass:[MyAnnotation class]])
    {
        MyAnnotation *customAnnotation = annotation;

        static NSString *annotationIdentifier = @"MyAnnotation";
        MKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:annotationIdentifier];
        if (!annotationView)
        {
            annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:annotationIdentifier];
            annotationView.canShowCallout = YES;
            annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        }
        else
        {
            annotationView.annotation = annotation;
        }

        annotationView.image = [UIImage imageNamed:customAnnotation.imageName];

        return annotationView;
    }

    return nil;
}

注意，animatesDrop是MKPinAnnotationView选项，您无法使用自定义注释视图。但如果你愿意，可以很容易地实现一个（参见How can I create a custom "pin-drop" animation using MKAnnotationView?）。我建议你首先解决基本的注释视图，然后再看看自定义注释视图投影动画。

为什么我的MKPointAnnotation不是自定义的？

1 个答案: