Problems Removing Annotations from a MKMapView
I am trying to remove all the annotations开发者_Python百科 of a map. The class that contains the MKMapView
implements the MKMapViewDelegate
. I am calling the remove all annotations method when a button (displayed in a modal view) is clicked. I am using the next code to remove all the annotations.
- (void)removeAllAnnotations {
NSMutableArray *annotationsToRemove = [NSMutableArray arrayWithCapacity:[self.mapView.annotations count]];
for (int i = 0; i < [self.mapView.annotations count]; i++) {
if ([[self.mapView.annotations objectAtIndex:i] isKindOfClass:[AddressAnnotation class]]) {
[annotationsToRemove addObject:[self.mapView.annotations objectAtIndex:i]];
}
}
[self.mapView removeAnnotations:annotationsToRemove];
}
The code works right but after calling the method, and when I try to add new annotations to the empty map, the class does not call to the viewForAnnotations
method and the annotations do not drop down and do not show a disclosure button into the annotation view. Why is this happening?
Thanks for reading.
Edited:
The annotations are shown but with out calling the view for annotation method (with out dropping down and with out including a disclosure button into the annotation view). Here is the method that I use to add the annotations and the viewForAnnotation
method.
- (void)loadAnnotations:(NSString *)type {
NSString *path = [[NSBundle mainBundle] pathForResource:@"PlacesInformation" ofType:@"plist"];
NSMutableArray *tmpArray = [[NSMutableArray alloc] initWithContentsOfFile:path];
for (int i = 0; i < tmpArray.count; i++) {
// Breaks the string down even further to latitude and longitude fields.
NSString *coordinateString = [[tmpArray objectAtIndex:i] objectForKey:@"coordinates"];
NSString *option = [[tmpArray objectAtIndex:i] objectForKey:@"type"];
if ([option isEqualToString:type]) {
CLLocationCoordinate2D currentCoordinate = [self stringToCoordinate:coordinateString];
AddressAnnotation *annotation = [[[AddressAnnotation alloc] initWithCoordinate:currentCoordinate] autorelease];
[self.mapView addAnnotation:annotation];
}
}
}
- (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation {
// If it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
else { // Handles the other annotations.
// Try to dequeue an existing pin view first.
static NSString *AnnotationIdentifier = @"AnnotationIdentifier";
MKPinAnnotationView *pinView = (MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:AnnotationIdentifier];
if (!pinView) {
// If an existing pin view was not available, creates one.
MKPinAnnotationView *customPinView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationIdentifier] autorelease];
customPinView.animatesDrop = YES;
customPinView.canShowCallout = YES;
// Adds a detail disclosure button.
UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[rightButton addTarget:self action:@selector(showDetails:) forControlEvents:UIControlEventTouchUpInside];
customPinView.rightCalloutAccessoryView = rightButton;
return customPinView;
} else
pinView.annotation = annotation;
}
return nil;
}
In viewForAnnotation, in the case where you are reusing a view, you are currently returning nil.
This else part:
} else
pinView.annotation = annotation;
Should probably be:
} else {
pinView.annotation = annotation;
return pinView;
}
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