MKAnnotation pin color update - ios

Question

In my app I am displaying a tableview which contains result of searched user from database. Now in that tableview there is one button by clicking on that user can see location of all searched users in map.when user first click on button he will be able to see all user's location with green color pin. I am displaying map in half part of view. Now When user select any particular searched user from table I want to change color of that user's pin.And if user select any other user from table previous selected user's pin color should be changed to as it was before.
I have tried this:
- (void)selectAnnotation:(id < MKAnnotation >)annotation animated:(BOOL)animated{
MKPinAnnotationView *chng=[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:nil];
chng.pinColor=MKPinAnnotationColorRed;
NSLog(#"========>selected");
}
And I am calling this method when user select particular user from table.
CLLocationCoordinate2D CurrentCoordinateSingleUser;
CurrentCoordinateSingleUser.latitude=[[singleUserPin objectAtIndex:1] doubleValue];
CurrentCoordinateSingleUser.longitude=[[singleUserPin objectAtIndex:2] doubleValue];
MapObjects *map1=[[MapObjects alloc]initwithCoordinate:CurrentCoordinateSingleUser title:[singleUserPin objectAtIndex:0] subtitle:Nil];
[userMap addAnnotation:map1];
for (id<MKAnnotation> currentAnnotation in userMap.annotations) {
if ([currentAnnotation isEqual:annotationToSelect]) {
[userMap selectAnnotation:currentAnnotation animated:FALSE];
}
}
But here selectAnnotation is not working.
UPDATE::
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
if([annotation isKindOfClass:[MKUserLocation class]])
return nil;
static NSString *identifier = #"myAnnotation";
MKPinAnnotationView * annotationView = (MKPinAnnotationView*)[userMap dequeueReusableAnnotationViewWithIdentifier:identifier];
if([annotation isEqual:map1]){
annotationView.pinColor = MKPinAnnotationColorRed;
}
else {
if (!annotationView)
{
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
// if(fromSelectedTab==TRUE){
// annotationView.pinColor = MKPinAnnotationColorRed;
// annotationView.animatesDrop = NO;
// fromSelectedTab=FALSE;
// }
// else{
annotationView.pinColor = MKPinAnnotationColorGreen;
annotationView.animatesDrop = NO;
// }
annotationView.canShowCallout = YES;
// annotationView.dr
}
else {
annotationView.annotation = annotation;
}
}
//annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
return annotationView;
}
MapObjects.h:
#interface MapObjects : NSObject<MKMapViewDelegate,MKAnnotation>
{
NSString *title,*subtitle;
CLLocationCoordinate2D coordinate;
}
#property(nonatomic,copy)NSString *title;
#property(nonatomic,copy)NSString *subtitle;
#property(nonatomic) CLLocationCoordinate2D coordinate;
-(MapObjects *)initwithCoordinate:(CLLocationCoordinate2D)coordinate title:(NSString *)title subtitle:(NSString *)subtitle;
#end

Answer 1

Use :
- (MKAnnotationView *)viewForAnnotation:(id <MKAnnotation>)annotation;
instead of creating a new MKPinAnnotationView. Or if it's in purpose you have to add somewhere the new annotation in your map.
Hope that will help

Answer 2

You should override MKMapiew method
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation (id<MKAnnotation>)annotation {
static NSString *identifier = #"PinAnnotation";
// map1 should be visible in method context
if ([annotation isEqual:map1]) {
MKPinAnnotationView *pinAnnotation = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
pinAnnotation.pinColor = MKPinAnnotationColorRed;// or any you want
return pinAnnotation;
}
return nil;
}
There you can determine specified annotation and set it desired color.

Answer 3

in viewDidLoad:
- (void)viewDidLoad {
[super viewDidLoad];
// There you should have selected "user" object and "users" array
...
// _annotations is declared in header
_annotations = [[NSMutableArray alloc] initWithCapacity:0];
for (UserObj *obj in users) {
CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(0.f, 0.f);
coordinate.latitude = obj.latitude;
coordinate.longitude = obj.longitude;
MapObjects *userAnnotation = [[MapObjects alloc] initWithCoordinate:coordinate title:obj.name subtitle:nil];
[map addAnnotation:userAnnotation];
[_annotations addObject:userAnnotation];
}
...
}
- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKPinAnnotationView *)view {
view.pinColor = MKPinAnnotationColorRed;
}
- (void)mapView:(MKMapView *)mapView didDeselectAnnotationView:(MKPinAnnotationView *)view {
view.pinColor = MKPinAnnotationColorGreen;
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation (id<MKAnnotation>)annotation {
static NSString *identifier = #"PinAnnotation";
MKPinAnnotationView *pinAnnotation = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if(!pinAnnotation) {
pinAnnotation = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
}
pinAnnotation.pinColor = MKPinAnnotationColorGreen;
return pinAnnotation;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// You should keep your annotation objects in some array too because map.annotations won't return annotation in order that we need
// After you add annotation to map, add them to NSMutableArray too, [_annotations addObject:userAnnotation];
MapObjects annotation = _annotations[indexPath.row];// not sure that it return that exact annotation
[map selectAnnotation:annotation animated:YES];
}