Question

在我的应用程序中，我通过显示计数来使用簇引脚机制，如果引脚上的计数大于1，我使用一种类型的图像'groupPin.png'，如果它等于1 i使用另一个图像'singlePin.png'，当从一个缩放级别更改为其他缩放级别时，地图视图没有显示确切的图像，它显示了组图像'groupIn.png'，其中包含另一个簇的引脚数上一个缩放级别而不是图像'singlePin.png'。从一个缩放级别转到另一个缩放级别时，它会发生很多次。我不知道为什么引脚会像这样更新。我发布了在地图视图上添加引脚的代码。请告诉我这种行为的解决方案。

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

      if([annotation isKindOfClass:[MKUserLocation class]])
           return nil;
      if(![annotation isKindOfClass:[CustomAnnotation class]])
           return nil;
      MKAnnotationView *pin = (MKAnnotationView *) [self.mapView   dequeueReusableAnnotationViewWithIdentifier:@"annotationPin"];

      if (pin == nil) 
      {
           pin = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"annotationPin"] autorelease];
      }
      NSString *status = ((CustomAnnotation*).annotation).subtitle;
      if([status isEqualToString:@"grouping"])
      {
            // image with count on it.
            UIImage *image = [UIImage imageNamed:@"groupPin.png"];
            pin.image = countImage;
      }
      else
      {
            pin.image = [UIImage imageNamed:@"singlePin.png"];
            pin.canShowCallout = YES;
      }
      return pin;
 }

//将引脚添加到地图视图

 - (void) addAnnotationPinsToCurrentRegion:(NSArray*) customPins
 {
      CustomAnnotation *annotation = nil;
      NSMutableArray *customAnnotations = [[NSMutableArray alloc] init];

      if([mapView.annotations count] != 0)
      {
          NSMutableArray *removedAnnotations = [[NSMutableArray alloc] initWithArray: mapView.annotations];
          [removedAnnotations removeObject: mapView.userLocation];
          [mapView removeAnnotations: removedAnnotations];
          [removedAnnotations release];
      }

      for (NSDictionary *dictionary in customPins)
      {
          int count = [[dictionary objectForKey:@"CUSTOMCOUNT"]intValue];
          float latitude = [[dictionary objectForKey:@"LATITUDE"]floatValue];
          float longitude = [[dictionary objectForKey:@"LONGITUDE"]floatValue]; 
          CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude);
          if(count > 1)
          {
              annotation = [[CustomAnnotation alloc] initWithCoordinate:locationCoordinate];
              annotation.title = @"title";
              annotation.subtitle = @"grouping";
              annotation.count = count;
          }
          else
          if(count == 1)
          {
              annotation = [[CustomAnnotation alloc] initWithCoordinate:locationCoordinate];
              annotation.title = [dictionary objectForKey:@"TITLE"];
              annotation.subtitle = [dictionary objectForKey:@"SUBTITLE"];
          }
          [customAnnotations addObject:annotation];
          [annotation release];
      }
      [mapView addAnnotations:customAnnotations];
      [customAnnotations release];
   }

使用群集引脚时，地图视图上的引脚无法正确更新

0 个答案: