Load mapview in the correct way - iphone

Question

I am loading a mapview with annotation. I have written the code as shown below. As I am new to OOPS I know that I may have committed a lot of mistakes. It would be really helpful, if someone would review my code and give some suggestions.
- (void)viewDidLoad
{
[super viewDidLoad];
if(groupOrContactSelected){
UIBarButtonItem *infoButtonItem = [[UIBarButtonItem alloc] initWithCustomView:self.infoButton];
UIBarButtonItem *segmentedButton = [[UIBarButtonItem alloc] initWithCustomView:segmentedControl];
flexibleSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
NSArray *toolbarItems = [NSArray arrayWithObjects: infoButtonItem, flexibleSpace, segmentedButton, nil];
[self setToolbarItems:toolbarItems];
self.navigationController.toolbar.translucent = true;
self.navigationController.toolbarHidden = NO;
[infoButtonItem release];
[segmentedButton release];
[flexibleSpace release];
mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
mapView.delegate=self;
[self.view addSubview:mapView];
addressbook = ABAddressBookCreate();
for (i = 0; i<[groupContentArray count]; i++) {
person = ABAddressBookGetPersonWithRecordID(addressbook,[[groupContentArray objectAtIndex:i] intValue]);
ABMultiValueRef addressProperty = ABRecordCopyValue(person, kABPersonAddressProperty);
NSArray *address = (NSArray *)ABMultiValueCopyArrayOfAllValues(addressProperty);
for (NSDictionary *addressDict in address)
{
addAnnotation = nil;
firstName = (NSString *)ABRecordCopyValue(person, kABPersonFirstNameProperty);
lastName = (NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty);
NSString *country = [addressDict objectForKey:#"Country"];
NSString *streetName = [addressDict objectForKey:#"Street"];
NSString *cityName = [addressDict objectForKey:#"City"];
NSString *stateName = [addressDict objectForKey:#"State"];
NSString *fullAddress = [streetName stringByAppendingFormat:#"%#/%#/%#", cityName, stateName, country];
mapCenter = [self getLocationFromAddressString:fullAddress];
if(stateName != NULL || country != NULL || streetName != NULL || cityName != NULL){
addAnnotation = (SJAddressAnnotation *)[mapView dequeueReusableAnnotationViewWithIdentifier:[groupContentArray objectAtIndex:i]];
if(addAnnotation == nil){
addAnnotation = [[[SJAddressAnnotation alloc] initWithCoordinate:mapCenter title:firstName SubTitle:lastName Recordid:[groupContentArray objectAtIndex:i] ] autorelease];
[mapView addAnnotation:addAnnotation];}
}
}
CFRelease(addressProperty);
}
[self zoomToFitMapAnnotations:mapView];
[self.navigationItem setHidesBackButton:YES animated:YES];
NSString *mapTitle = localizedString(#"MAP_TITLE");
[self setTitle:mapTitle];
[segmentedControl addTarget:self action:#selector(segmentAction:) forControlEvents:UIControlEventValueChanged];
NSString *close = localizedString(#"CLOSE");
UIBarButtonItem *closeButton = [[UIBarButtonItem alloc] initWithTitle:close style:UIBarButtonItemStylePlain target:self action:#selector(onClose:)];
self.navigationItem.rightBarButtonItem = closeButton;
self.navigationController.navigationBar.barStyle = UIBarStyleBlackTranslucent;
[closeButton release];
}
[searchDirectionSegmentedControl release];
[mapView release];
}
I may have committed a lot of mistakes. All suggestions will be appreciated. Thanks

Answer 1

Here is link which you can prefer and know how to structure the code properly http://www.highoncoding.com/Articles/804_Introduction_to_MapKit_Framework_for_iPhone_Development.aspx
Hope this help you.