im trying to create a show on map section 开发者_运维知识库in my app, but for some reason the annotations will not place correctly
MKMapView *mapView = (MKMapView*)self.view;
CLLocationCoordinate2D coordinate;
coordinate.latitude = 55.065767;
coordinate.longitude = -2.724609;
mapView.region = MKCoordinateRegionMakeWithDistance(coordinate, 500000, 500000);
mapView.delegate = self;
for (int i=0; i<1; i++) {
coordinate.latitude = latitude;
coordinate.longitude = longitude;
CLLocationCoordinate2D newCoord = {coordinate.latitude, coordinate.longitude};
PlaceAnnotation* annotation = [[PlaceAnnotation alloc] initWithCoordinate:newCoord];
//annotation.mTitle = companyTitle;
//annotation.mSubtitle = companyDescription;
[mapView addAnnotation:annotation];
[annotation release];
}
}
and in my place annotaion
- (id)initWithCoordinate:(CLLocationCoordinate2D)coordinate{
self = [super init];
if (self != nil) {
_coordinate = coordinate;
}
return self;
}
lattitude and longditude both have the right values, i have used this code before but using an array pointing to an object and it works fine , but when i try to give it the values directly it fails
can anyone help me out
*edit , sorry i already have my Viewforannotation just got missed out in the copy
- (MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:(id <MKAnnotation>)annotation
{
MKPinAnnotationView *pinAnnotation = nil;
if(annotation != mV.userLocation)
{
static NSString *defaultPinID = @"myPin";
pinAnnotation = (MKPinAnnotationView *)[mV dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
if ( pinAnnotation == nil )
pinAnnotation = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:defaultPinID] autorelease];
pinAnnotation.canShowCallout = YES;
//instatiate a detail-disclosure button and set it to appear on right side of annotation
}
return pinAnnotation;
[pinAnnotation release];
}
Your PlaceAnnotation needs to implement the MKAnnotation protocol. Specifically, the method
- (CLLocationCoordinate)coordinate;
or you can define the property and set it in your constructor
@property (assign) CLLocationCoordinate coordinate
This is how the MKMapView knows where to place the annotation.
p.s. Also, I'm not sure how kosher this is:
CLLocationCoordinate2D newCoord = {coordinate.latitude, coordinate.longitude};
It's probably fine, but Apple recommend:
CLLocationCoordinate2D newCoord = CLLocationCoordinate2DMake(coordinate.latitude, coordinate.longitude);
You need to implement the MKMapViewDelegate protocol method
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
to supply an MKAnnotationView instance (or subclass) to use to display the annotation. Go see the MKMapViewDelegate protocol reference for details.
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