适用于iOS的mapkit中的didupdateuserlocation方法？

Question

I m trying to give 5 annotations around user location MKMapView...I m choosing random values to annotations in my didupdateuserlocation method...when i run my projet all 5 annotations showing in a centre of the earth at a same place..its showing in sea area near to africa...anyone help me change different locations for annotations.

- (void)mapView:(MKMapView *)mv didUpdateUserLocation:(MKUserLocation *)userLocation
{
    CLLocationCoordinate2D userCoordinate = userLocation.location.coordinate;
    for(int i = 1; i<=5;i++)

    {
        CGFloat latDelta = rand()*.035;       ///RAND_MAX -5.0;
        NSLog(@"%f",latDelta);
        CGFloat longDelta = rand()*.03;       ///RAND_MAX -5.0;
        NSLog(@"%f",longDelta);
        CLLocationCoordinate2D newCoord = { userCoordinate.latitude + latDelta, userCoordinate.longitude + longDelta };
        MapPoint *mp = [[MapPoint alloc] initWithCoordinate:newCoord title:[NSString stringWithFormat:@"Azam Home %d",i] subTitle:@"Home Sweet Home"];    
        [mv addAnnotation:mp];
    }

}

i printed my random values..they are

2012-01-02 20:27:32.229 ShareImg[749:15803] 588.244995
2012-01-02 20:27:32.230 ShareImg[749:15803] 8474257.000000
2012-01-02 20:27:32.231 ShareImg[749:15803] 56792752.000000
2012-01-02 20:27:32.231 ShareImg[749:15803] 29548310.000000
2012-01-02 20:27:32.231 ShareImg[749:15803] 40043812.000000
2012-01-02 20:27:32.231 ShareImg[749:15803] 14106338.000000
2012-01-02 20:27:32.231 ShareImg[749:15803] 3535964.000000
2012-01-02 20:27:32.232 ShareImg[749:15803] 43735528.000000
2012-01-02 20:27:32.232 ShareImg[749:15803] 51057228.000000
2012-01-02 20:27:32.232 ShareImg[749:15803] 60217132.000000

help me with this...

Answer 1

CLLocationCoordinate2D is a structure of two CLLocationDegrees. CLLocationDegrees is a double, which presents position in degrees
From documentation :

latitude
The latitude in degrees. Positive values indicate latitudes north of the equator. Negative values indicate latitudes south of the equator.
longitude
The longitude in degrees. Measurements are relative to the zero meridian, with positive values extending east of the meridian and negative values extending west of the meridian.

So latitude must be between -90 and 90, and longitude must be between -180 and 180. Your random position is to large, and mapkit shows you position 0, 0 which is in Gulf of Guinea.

Answer 2

Maybe your values for lat and lon are not valid? Try with this snippet

CGFloat latDelta = userCoordinate.latitude+(i*0.000010);
CGFloat longDelta = userCoordinate.longitude+(i*0.000010);

The values that you have generated seems very strange for latitude and longitude! Example Berlin Cafe Kranzler has the values

52.504039 13.330925