Question

I am developing an application in which i need to show multiples events location at same time and i have two types of events(my events and all events). I give opportunity to switch between my events and all events through segment control, First it show all events location and when user switch to my events it’ll delete or hide all events location(pins) and show my events location pins on same map view. I’ve bit confusion how to handle this to reload or refresh map view with new pins?

Answer 1

You may try this…

    //Remove or hide all annotations
for (id annotation in mapView.annotations) {
    if (annotation != mapView.userLocation) {
        [[mapView viewForAnnotation:annotation] setHidden:YES]; // You can remove as well
    }
}

/code to remove annotations instead of hiding/

    NSMutableArray *listRemoveAnnotations = [[NSMutableArray alloc] init];
for (id annotation in mapView.annotations) {
    if (annotation != mapView.userLocation) {
        [listRemoveAnnotations addObject:annotation];
    }
}
[mapView removeAnnotations:listRemoveAnnotations];
[listRemoveAnnotations release];

When all annotations are dealt with then:

• if all annotations are hidden, un-hide the annotations you wish to show.
• if all annotations are removed, add annotations you wish to show.