Question

I need to display multiple annonation views in MKMapKit..I use this code..

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib

    [mapView setMapType:MKMapTypeStandard];
    [mapView setZoomEnabled:YES];
    [mapView setScrollEnabled:YES];
    DisplayMap *ann = [[DisplayMap alloc] init];
    //NSLog(@"xapp.arrplacename:%d",[xapp.arrplacename count]);
    for (i=0;i<=[arrplacename count]-1;i++)
    {

        MKCoordinateRegion region = { {0.0, 0.0 }, { 0.0, 0.0 } };
        //arrplacename contains the address of the locations
        NSString *straddress=[arrplacename objectAtIndex:i];
        NSString *strregion=@"";
        NSString *strs=[straddress stringByAppendingString: strregion];
        //  lbladdress.text=strs;
        //  NSString add=strs;
        // here you define the url setting your address
        NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%@&output=csv",[strs stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]];

        NSLog(@"US: %@",urlString);

        // then you get the response string here
        NSString *locationString = [[[NSString alloc] initWithContentsOfURL:[NSURL URLWithString:urlString]] autorelease];
        NSLog(@"loaction strings%@",locationString);
        // now you can create an array splitting the response values using the ","
        //[listItems addObject:locationString];
        listItems = [locationString componentsSeparatedByString:@","];

        NSLog(@"A: %@",[xapp.listItems objectAtIndex:2]);

        // define latitude and longitude variables
        double latitude  = 0.0;
        double longitude = 0.0;

        NSString *strlatitude;
        NSString *strlongitude;

        strlatitude=[xapp.listItems objectAtIndex:2];
        strlongitude=[xapp.listItems objectAtIndex:3];

        float stringFloat = [strlatitude floatValue]; 
        float string1Float = [strlongitude floatValue]; 

        // if your array has inside the sctructure you aspect (4 values as described in my previous post) and the first value is like "200" (OK result)
        if([xapp.listItems count] >= 4 && [[xapp.listItems objectAtIndex:0] isEqualToString:@"200"]) 
        {
            // not sure if you need the accurancy parameter
            //accurancy = [[listItems objectAtIndex:1] intValue];

            // here you can get your values

            // latitude = [[listItems objectAtIndex:2] doubleValue];
            //longitude = [[listItems objectAtIndex:3] doubleValue];

            latitude = stringFloat;
            longitude = string1Float;

        }
        else {
            NSLog(@"Error on map");
        }
        region.center.latitude = latitude;
        region.center.longitude = longitude;
        NSLog(@"latitude:%g",region.center.latitude);
        //  region.center.latitude = 42.7157850;
        // region.center.longitude = 27.56470180;

        region.span.longitudeDelta = 0.01f;
        region.span.latitudeDelta = 0.01f;
        [mapView setRegion:region animated:YES];
        [mapView setDelegate:self];
        ann.title = [xapp.arrplacename objectAtIndex:i];
        ann.subtitle = [xapp.arrplacename objectAtIndex:i];
        ann.coordinate = region.center;
        [mapView addAnnotation:ann];

    }

}

I do have some problems in this code….all the coordnates are not added to the listitems array..I can see only the objects that are added atlast….

This is the delegates I add for displaying the annonation in my map..

- (CLLocationCoordinate2D) geoCodeUsingAddress:(NSString *)address{

    NSLog(@"ssssss");

    double latitude = 0, longitude = 0;
    NSString *esc_addr = [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSString *req = [NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?sensor=false&address=%@", esc_addr];
    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] encoding:NSUTF8StringEncoding error:NULL];
    if (result) {
        NSScanner *scanner = [NSScanner scannerWithString:result];
        if ([scanner scanUpToString:@"\"lat\":" intoString:nil] && [scanner scanString:@"\"lat\":" intoString:nil]) {
            [scanner scanDouble:&latitude];
            if ([scanner scanUpToString:@"\"lng\":" intoString:nil] && [scanner scanString:@"\"lng\":" intoString:nil]) {
                [scanner scanDouble:&longitude];
            }
        }
    }
    CLLocationCoordinate2D center;
    center.latitude = latitude;
    center.longitude = longitude;

    return center;
}


-(MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:
(id <MKAnnotation>)annotation {

   MKPinAnnotationView *pinView = nil;
    NSLog(@"pinnview before release %d",[pinView retainCount]);

    if (pinView !=nil) {
        pinView =nil;
        [pinView release];
    }
    NSLog(@"pinnview after release %d",[pinView retainCount]);

    // if it's the user location, just return nil.
    if ([annotation isKindOfClass:[MKUserLocation class]])
        return nil;

    if(annotation != mapView.userLocation)
    {

        static NSString *defaultPinID = @"your-pin";

        pinView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];

        if ( counting < [mapView.annotations count])
        {
            counting++;

            pinView = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:defaultPinID] autorelease];


           /* for(DisplayMap* a in mapView.annotations)
            {
                if (annotation == a){
                    pinView.image =
                    [UIImage imageWithContentsOfFile:
                     [[NSBundle mainBundle] pathForResource:a.image ofType:nil]];   
                }
            }*/
            pinView.centerOffset= CGPointMake(0,-10);
            pinView.canShowCallout = YES;


        }

    }

   // return pinView;


}

- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
    NSLog(@"enter");
    [mapView selectAnnotation:[[mapView annotations] lastObject] animated:YES];
}

Delegates are called only once eventhough I’m using [mapView addAnnotation:ann]; inside the for loop…And it shows pin only for the last item tatz added in the array…How can I overcome this????

Answer 1

You are allocating and initializing ‘ann’ only once before the for loop starts, and you are altering the same and adding it again and again into Map. Thats why you are getting only one annotation.

Move this line inside for loop and try,

DisplayMap *ann = [[DisplayMap alloc] init];