在我的应用程序中，我们有一个带有MKMapView的屏幕。
此地图显示了一堆地点的引脚（位置是应用中定义的模型）。
在模拟器中运行时，这很好用。但是，当在设备上运行时，引脚似乎消失并且几乎每次平移地图时都会重新出现。即使轻微的触摸和移动也可能导致地图显示和隐藏引脚。
地图不是特别繁忙，即使显示一个引脚也会显示并隐藏它。
有谁知道为什么会这样？我在下面粘贴了我的代码......这是一个Rubymotion应用程序，所以代码是Ruby。
我在下面添加了与此Ruby代码等效的Objective C。抱歉，如果有一些拼写错误或惯用错误，那我已经写了一段时间了。
观察记录器，我可以看到每次地图引脚消失/重新出现时都会调用mapView:viewForAnnotation。
每次mapView:regionDidChangeAnimated我都可以看到注释的对象ID是相同的 - 所以我认为它们不被删除（它们不应该被删除）
# ====================
# = MKMapKitDelegate =
# ====================
# Don't react if the user has moved less than three meters
USER_MOVE_THRESHOLD = 3
# The user location has changed
def mapView(mapView, didUpdateUserLocation: newLocation)
NSLog("mapView:didUpdateUserLocation")
return unless userLocation
coord = newLocation.coordinate
newLocationAsCL = CLLocation.alloc.initWithCoordinate(coord, altitude: 1, horizontalAccuracy:1, verticalAccuracy: -1, timestamp: nil)
meters = newLocationAsCL.distanceFromLocation(@lastUserCLLocation)
# If user has moved less than 3m, return
if meters > 0 and meters < USER_MOVE_THRESHOLD
log "Distance was less than #{USER_MOVE_THRESHOLD} meters (#{meters}) - returning ***"
return
end
# If the coord is the same as the previous user location
if userLocation.coordinate.latitude == coord.latitude && userLocation.coordinate.longitude == coord.longitude
log "User hasn't moved - returning ***"
else
log 'User has moved'
end
log "Did update user location: #{coord.latitude},#{coord.longitude}"
if coord.latitude.to_f == 0.0 and coord.longitude.to_f == 0.0
log 'Invalid coordinate received - returning ***'
else
fetchLocationsFromAPI
end
end
def mapView(mapView, regionDidChangeAnimated: animated)
NSLog("mapView:regionDidChangeAnimated:#{animated}")
# do nothing here yet...
end
# create map pins...
def mapView(mapView, viewForAnnotation: annotation)
log "mapView:viewForAnnotation: #{annotation.inspect}"
if annotation.is_a?(Location)
# If there's already an annotation we can use, use it! Otherwise create a new one
annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier(annotation.class.to_s) || begin
annotationView = MKPinAnnotationView.alloc.initWithAnnotation(annotation, reuseIdentifier: annotation.class.to_s)
annotationView.enabled = true
annotationView.canShowCallout = true
annotationView.animatesDrop = false
annotationView.pinColor = MKPinAnnotationColorRed
rightButton = UIButton.buttonWithType(UIButtonTypeDetailDisclosure)
rightButton.addTarget(self, action: 'showLocationScreen:', forControlEvents: UIControlEventTouchUpInside)
annotationView.rightCalloutAccessoryView = rightButton
annotationView
end
annotationView.annotation = annotation
annotationView.rightCalloutAccessoryView.tag = @mapLocations.index(annotation)
return annotationView
end
end
def mapView(mapViewm, didAddAnnotationViews: views)
NSLog("mapView:didAddAnnotationViews - #{views}")
# do nothing here yet...
end
#define kUserMoveThreshold 1
-(void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)newLocation
{
NSLog(@"mapView:didUpdateUserLocation")
if (!userLocation) {
return;
}
CLLocationCoordinate2D coord = newLocation.coordinate;
CLLocation newLocationAsCL = [[CLLocation alloc] initWithCoordinate: coord altitude: 1 horizontalAccuracy: 1 verticalAccuracy: -1 timestamp: NULL];
CLLocationDistance meters = [newLocationAsCL distanceFromLocation: lastUserCLLocation];
// If user has moved less than 3m, return
if (meters > 0 && meters < kUserMoveThreshold){
NSLog(@"Distance was less than %d meters (%d) - returning ***", kUserMoveThreshold, meters);
return;
}
// If the coord is the same as the previous user location
if (userLocation.coordinate.latitude == coord.latitude && userLocation.coordinate.longitude == coord.longitude){
NSLog(@"User hasn't moved - returning ***");
return;
} else {
NSLog(@"User has moved");
}
NSLog(@"Did update user location: %f,%f", coord.latitude, coord.longitude);
if (coord.latitude == 0.0 && coord.longitude == 0.0){
NSLog(@"Invalid coordinate received - returning ***");
} else {
[self fetchLocationsFromAPI];
}
}
-(void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated
{
NSLog(@"mapView:regionDidChangeAnimated: %s", animated ? @"TRUE" : @"FALSE");
}
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id < MKAnnotation >)annotation
{
NSLog(@"mapView:viewForAnnotation %s", annotation.description);
if ([annotation isKindOfClass: [Location class]]){
// If there's already an annotation we can use, use it! Otherwise create a new one
MKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier: [annotation className]];
if (!annotationView){
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation: annotation reuseIdentifier: [annotation className]];
[annotationView setEnabled: YES];
[annotationView setCanShowCallout: YES];
[annotationView setAnimatesDrop: NO];
[annotationView setPinColor: MKPinAnnotationColorRed];
UIButton *rightButton = [UIButton buttonWithType: UIButtonTypeDetailDisclosure];
[rightButton addTarget: self action: @selector(showLocationScreen:) forControlEvents: UIControlEventTouchUpInside];
[annotationView setRightCalloutAccessoryView: rightButton];
}
[annotationView annotation: annotation];
[[annotationView rightCalloutAccessoryView] setTag: [mapLocations indexOfObject: annotation]];
return annotationView
}
}
-(void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
NSLog(@"mapView:didAddAnnotationViews %@", views)
}
答案 0 :(得分：2)
这是Rubymotion的一个错误，似乎已经在1.30版本中解决了
= RubyMotion 1.30 =
...
...
答案 1 :(得分：0)
创建引脚注释时，是否要将它们添加到mapView的注释数组中？
CLLocationCoordinate2D locationForSelectedFloorOffice;
locationForSelectedFloorOffice.longitude = [[myGeoCode objectAtIndex:0] floatValue] * 1.0;
locationForSelectedFloorOffice.latitude = [[myGeoCode objectAtIndex:1] floatValue] * 1.0;
MyLocation *annotation = [[MyLocation alloc] initWithName:dStore.selectedFloorRoomName address:@" " coordinate:locationForSelectedFloorOffice];
[self.mapView addAnnotation:annotation];