CLLocation *lastLocation = [[CLLocation alloc] initWithLatitude:coords.latitude longitude:coords.longitude];
  CLLocation *nowLocation = [[CLLocation alloc] initWithLatitude:location.coordinate.latitude longitude:location.coordinate.longitude];
 
    int distanceMeters = [lastLocation distanceFromLocation:nowLocation];
             
                if(appDelegate.isKMOrMILE == 0)
                {
                    [cardistanceLabel setText:[NSString stringWithFormat:@"%d KM",distanceMeters/1000]];//公里
                }
                else if(appDelegate.isKMOrMILE == 1)
                {
                    int data = (distanceMeters/1000)/1.6093;
                    [cardistanceLabel setText:[NSString stringWithFormat:@"%d MILE",data]];//英里
                }





已知两地经纬度 计算两地之间的距离： 
 
//    地图显示当前位置： 
 
    mapView.showsUserLocation=YES; 
 
    CLLocationManager *locationManager = [[CLLocationManager alloc] init];//创建位置管理器 
 
    locationManager.delegate=self;//设置代理 
 
    locationManager.desiredAccuracy=kCLLocationAccuracyBest;//指定需要的精度级别为最佳精度 
 
    locationManager.distanceFilter=1000.0f;//设置距离筛选器为任何移动都要发送更新 
 
    [locationManager startUpdatingLocation];//启动位置管理器 
 
    MKCoordinateSpan theSpan; 
 
    //地图的范围 越小越精确 
 
    theSpan.latitudeDelta=0.05; 
 
    theSpan.longitudeDelta=0.05; 
 
    MKCoordinateRegion theRegion; 
 
    theRegion.center=[[locationManager location] coordinate]; 
 
    theRegion.span=theSpan; 
 
    [mapView setRegion:theRegion]; 
 
    [locationManager release]; 
 
     
 
    MKUserLocation *usrLoc=mapView.userLocation; 
 
    CLLocationCoordinate2D usrCoordinate=usrLoc.location.coordinate; 
 
    NSLog(@"la==%f lo==%f",usrCoordinate.latitude,usrCoordinate.longitude); 
 
     
 
//   已知两点的经纬度，计算出两地距离： 
 
    CLLocation *location1 = [[[CLLocation alloc] initWithLatitude:usrCoordinate.latitude longitude:usrCoordinate.longitude] autorelease]; 
 
    CLLocation *location2 = [[[CLLocation alloc] initWithLatitude:36.676445 longitude:117.106793] autorelease]; 
 
    NSLog(@"JULI====%.0f km", [location1 distanceFromLocation:location2]);//4502




取小数点后两位(四舍五入)，输出：
NSLog(@"%.02f km",4478.442312);