MapView not reloading annotations unless you zoom in or move map - iphone

Question

I am using the following for loop to manage/find out the five nearest annotations to the user location, and then set them as the mapView's annotations.
for (int i = 0; i <= 5; i++) {
//NSLog(#"Stores Count For Loop: %i", [storesLessThan100KAway count]);
if ([storesLessThan100KAway count] > 5) {
NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:#"distanceToTarget" ascending:YES];
NSArray *newArray = [storesLessThan100KAway sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]];
[mapView addAnnotation:[newArray objectAtIndex:i]];
if ([[mapView annotations] count] > 4) {
[descriptor release];
[dict release];
[currentlocation release];
[usrlocation release];
[annotation release];
[paul drain];
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
return;
}
}
However the annotations added to the map will not be shown until the map is zoomed in or moved. Is there anyway that I could stop this?

Answer 1

MKMapView is a subclass of UIView -- You could try calling [mapView setNeedsDisplay]?
If that doesn't work:
// Force update of map view.
CLLocationCoordinate2D center = [mapView centerCoordinate];
[mapView setCenterCoordinate:center];

Answer 2

Try to put these lines in a Timer and stop it after you finish adding annotations
static float deltaX=.1;
CLLocation *location = [[[CLLocation alloc] initWithLatitude:self.mapView.centerCoordinate.latitude longitude:self.mapView.centerCoordinate.longitude] autorelease];
MKCoordinateRegion region;
region.center = location.coordinate;
MKCoordinateSpan span;
span.latitudeDelta = self.mapView.region.span.latitudeDelta+deltaX;
span.longitudeDelta = self.mapView.region.span.longitudeDelta+deltaX;
deltaX+=.1;
deltaX*=-1;
region.span = span; // Set the region's span to the new span.
[self.mapView setRegion:region animated:0];