place pin on mapview by coordinates sent from appdelegate - iphone

Question

This takes me days..I could not make it work.
I write a method that places a pin on map as below:
- (void) SetMaps:(NSString *)Lats :(NSString *)lons;
{
if([upLo isEqualToString:#"Y"])
{
NSLog(#"setting maps:%#,%#",Lats,lons);
[mapView setMapType:MKMapTypeStandard];
[mapView setZoomEnabled:YES];
[mapView setScrollEnabled:YES];
[mapView setMapType:MKMapTypeStandard];
[mapView setZoomEnabled:YES];
  [mapView setScrollEnabled:YES];
MKCoordinateRegion region = { {0.0, 0.0 }, { 0.0, 0.0 } };
region.center.latitude = [Lats doubleValue] ;
region.center.longitude = [lons doubleValue];
region.span.longitudeDelta = 0.01f;
region.span.latitudeDelta = 0.01f;
[mapView setRegion:region animated:YES];
[mapView setDelegate:self];
MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
point.coordinate = region.center;
[self.mapView addAnnotation:point];
}
}
This method runs well if I call it in secondViewController.m in a tab bar controll application.
But, I want to call it from appdelegate.m.
So in appdelegate.m, I put
secondViewController *Gper=[[secondViewController alloc]init];
[Gper SetMaps:LAT:LON];
[Gper release];
from this NSLog(#"setting maps:%#,%#",Lats,lons); I can see the lat and lons values are correct into this method.
However, the map doesnt change to this location.
Whatelse should I do to make it showing new location?
Thanks for any help.

Answer 1

I feel you should learn (Objective-)C memory management and Cocoa conventions better before doing anything further. + alloc returns a new instance of your view controller class, and not the one that is currently displayed.
And begin your class names with a capital letter. And your method names with a lowercase one.