MKMapView 根据布尔值自定义引脚

Question

我有大约 190 个自定义图钉的 MKMap。我想根据布尔值更改引脚图像。但是我已经制作了静态布尔值，并且在 -(void)Map 中，我从 Parse 获取数据以及所有布尔值。当我在自定义引脚的委托方法中使用 If/Else 时，所有布尔值都变为 FALSE。

-(void)Map{
    CLLocation *userLoc = self.mapView.userLocation.location;
    CLLocationCoordinate2D userCoordinate = userLoc.coordinate;

    NSLog(@"user latitude = %f",userCoordinate.latitude);
    NSLog(@"user longitude = %f",userCoordinate.longitude);

    self.mapView.delegate=self;
    NSMutableArray* annotations=[[NSMutableArray alloc] init];

    NSMutableArray *title = [self.itemss valueForKey:@"title"];
    NSMutableArray *subtitle = [self.itemss valueForKey:@"subtitle"];
    NSMutableArray *latitude = [self.itemss valueForKey:@"Lati"];
    NSMutableArray *longitude = [self.itemss valueForKey:@"Long"];
    NSMutableArray *gold = [self.itemss valueForKey:@"clubPurchased"];


    NSLog(@"%@", latitude);
    NSLog(@"%@", longitude);

    for (int i = 0; i < [title count]; i++){
        NSLog(@"%lu", (unsigned long)title.count);

        double lat = [[latitude objectAtIndex:i] doubleValue];
        double lng = [[longitude objectAtIndex:i] doubleValue];
        NSString *T = [title objectAtIndex:i];
        NSString *TT = [subtitle objectAtIndex:i];

         mine = [[gold objectAtIndex:i] boolValue];
        NSLog(@"BOOL:%hhd", mine);



        CLLocation *towerLocation = [[CLLocation alloc] initWithLatitude:lat longitude:lng];
        [annotations addObject:towerLocation];
        CLLocationCoordinate2D coord = [[annotations lastObject] coordinate];

        PlacePin * myAnnotation1=[[PlacePin alloc] init];

        myAnnotation1.coordinate=coord;
        myAnnotation1.title=T;
        myAnnotation1.subtitle=TT;

        [self.mapView addAnnotation:myAnnotation1];
        [SVProgressHUD dismiss];

        }



}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    NSLog(@"welcome into the map view annotation");

    // 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";
    MKAnnotationView* pinView = [[MKAnnotationView alloc]
                                    initWithAnnotation:annotation reuseIdentifier:AnnotationIdentifier];



    if (mine){
        pinView.image = [UIImage imageNamed:@"Iconn"];
       NSLog(@"TRUE");


    } else {
       NSLog(@"FALSE");

        pinView.image = [UIImage imageNamed:@"Iconn_gold"];


    }
    pinView.canShowCallout=YES;



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


    return pinView;
}

Answer 1

在 -(void)Map 中，mine 的值在 for 循环中发生了更改，它注册了循环中最后一项的值（这很可能是错误的）。

在viewForAnnotation 中，mine 的每个注释的值都没有改变，因此在显示注释时您会得到全部错误。

您需要将 mine 值保存到自定义注释 PlacePin 中的 -(void)Map 中的每个项目（就像 title 和 subtitle）并检索 viewForAnnotation 中的值作为 if -else 语句。

另外，您可能无法正确访问viewForAnnotation 中的自定义注释，您可以参考此post。

编辑 2：

我相信PlacePin 是您的自定义注释。在 PlacePin.h 文件中，

@interface PlacePin : NSObject <MKAnnotation>

@property(nonatomic, assign) CLLocationCoordinate2D coordinate;
@property(nonatomic, copy) NSString *title;
@property(nonatomic, copy) NSString *subtitle;
// Add this line
@property (strong, nonatomic) NSNumber *mine;

在 - (void)Map，

PlacePin * myAnnotation1=[[PlacePin alloc] init];

myAnnotation1.coordinate=coord;
myAnnotation1.title=T;
myAnnotation1.subtitle=TT;
// Save the boolean value here
myAnnotation1.mine=[gold objectAtIndex:i];

在 viewForAnnotation 中，试试这个：

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

    if ([annotation isKindOfClass:[PlacePin class]])
    {
        PlacePin *placePin = (PlacePin *)annotation;
        MKAnnotationView* pinView = (MKAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"AnnotationIdentifier"];

        if(pinView)
        {
            pinView.annotation = annotation;
        }
        else
        {
            // Edit 2: Note this line!!
            pinView = placePin.annotationView;
        }
        // Use this to check instead
        if ([pinView.mine boolValue])
        {
            pinView.image = [UIImage imageNamed:@"Iconn"];
            NSLog(@"TRUE");
        } 
        else 
        {
            NSLog(@"FALSE");
            pinView.image = [UIImage imageNamed:@"Iconn_gold"];
        }
        ...
    }
}