Google Maps on iOS: markers and route playback

English translation of the Chinese original, translated on 2026-10-23. The article body uses automated translation; app descriptions, historical reading notes and video subtitles receive separate editorial checks. Original publication dates, attribution, code and version notes are retained.

“iOS development is like moving things around; once you become skilled enough, you can start taking shortcuts.” Bison

The project I recently worked on needed its maps to match the Android client, which used Google Map rather than Baidu Maps.
To be honest, it was a bit troublesome. Before working alongside an Android client, I usually used Apple's built-in maps, Amap, or Baidu.
I had hardly worked with Google Maps before. The main code is below.

.h file

@property (strong, nonatomic) GMSMapView *_mapView;

.m file

// Create the map

- (void)creatMap{

    _mapView = [[GMSMapView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
    [self.view addSubview:_mapView];
    [_mapView clear];
    [self initMapView];
}

It consists of the following three parts.

- (void)initMapView
{

    GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-6.13631
    longitude:106.789352
    zoom:ZOOM_LEVEL];
    _mapView.mapType = kGMSTypeNormal;
    _mapView.camera = camera;
    _mapView.delegate = self;
    _geocoder = [[GMSGeocoder alloc] init];

    polyline = [[GMSPolyline alloc] init];
    linepath = [GMSMutablePath path];


    CLLocationCoordinate2D coords;
    coords.latitude = -6.136271;
    coords.longitude = 106.789216;


    _mapView.camera = [GMSCameraPosition cameraWithTarget:coords
    zoom:ZOOM_LEVEL];

    //显示标注
    GMSReverseGeocodeCallback handler = ^(GMSReverseGeocodeResponse *response,
    NSError *error) {
    if (response && response.firstResult) {

        GMSMarker *marker = [[GMSMarker alloc] init];
        marker.position = coords;
        marker.title = response.firstResult.addressLine1;
        marker.snippet = response.firstResult.addressLine2;
        _addressData = response.firstResult.addressLine2;
        [self refreshGpsInfo];
        marker.appearAnimation = kGMSMarkerAnimationNone;
        marker.icon = SETIMAGE(@"deviceannotation.png");
        marker.map = _mapView;
    } else {
        NSLog(@"Could not reverse geocode point (%f,%f): %@",
        coords.latitude, coords.longitude, error);
    }
    };

    [_geocoder reverseGeocodeCoordinate:coords
    completionHandler:handler];
    //画线，轨迹回放
    [linepath removeAllCoordinates];
    [self drawLineWithLocationArray:trackArray];


    /*
    注，trackArray里面的数据格式
    CLLocation *nowLocation = [[CLLocation alloc] initWithLatitude:coords.latitude longitude:coords.longitude];
    [trackArray addObject:nowLocation];

    */

}

// Draw a line for route playback

- (void)drawLineWithLocationArray:(NSArray *)locationArray
{

    if(current_type == _CURRENT_TRACK)
    polyline.strokeColor = [UIColor blueColor];
    else
    polyline.strokeColor = [UIColor redColor];
    polyline.strokeWidth = 6.f;

    // for(int idx = 0; idx < pointStrings.count; idx++)
    for(int idx = 0; idx < locationArray.count; idx++)
    {
    CLLocation *location = [locationArray objectAtIndex:idx];
    CLLocationDegrees latitude  = location.coordinate.latitude;
    CLLocationDegrees longitude = location.coordinate.longitude;

    // create our coordinate and add it to the correct spot in the array
    CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);
    [linepath addCoordinate:coordinate];
    }
    polyline.path = linepath;
    polyline.map = _mapView;
}

For the Google Api, register on Google's developer website and enter the relevant information about your own app to obtain an apikey.