iOS-在没有动画的情况下清除Google地图数据

我正在实施谷歌地图，我需要在每隔几秒（30-50秒）后清除地图数据（所有多段线+标记）。正如我们所知，我们可以使用

[yourMap clear]但当我这样做的时候，谷歌地图会制作一些动画（就在调用clear方法之后），然后它会在地图上显示新的数据，我不想要这个小动画。注意：我每隔20-50秒调用此方法drawPolylineOnMap\u ShowDriverRecurrentLoc，以在地图上显示最新数据

-(void)drawPolylineOnMap_ShowDriverCurrentLoc :(NSDictionary*)dicResponse
{
    // clear current map

    [mapViewGMS clear];

    NSString *driver_coordinates= [dicResponse valueForKey:@"one"];
    NSArray *itemsDriver = [driver_coordinates componentsSeparatedByString:@","];   //take the one array for split the string

    NSString *sourceLongi=[itemsDriver objectAtIndex:0];   //shows Description
    NSString *sourceLati=[itemsDriver objectAtIndex:1];   //


    NSString *clientLoc= [dicResponse valueForKey:@"two"];

    NSArray *itemsClient = [clientLoc componentsSeparatedByString:@","];   //take the one array for split the string

    NSString *destLongi=[itemsClient objectAtIndex:0];   //shows Description
    NSString *destLati=[itemsClient objectAtIndex:1];   //Shows Data


    CLLocation *myOrigin=[[CLLocation alloc]initWithLatitude:[sourceLati floatValue] longitude:[sourceLongi floatValue]];
    CLLocation *myDestination=[[CLLocation alloc]initWithLatitude:[destLati floatValue] longitude:[destLongi floatValue]];

    [self fetchPolylineWithOriginForDriverCurrLoc:myOrigin destination:myDestination completionHandler:^(GMSPolyline *polyline)
     {
         dispatch_async(dispatch_get_main_queue(), ^{
             if(polyline) {
                 polyline.map = mapViewGMS;
             }
         });
     }];
}

-(void)fetchPolylineWithOriginForDriverCurrLoc:(CLLocation *)origin destination:(CLLocation *)destination completionHandler:(void (^)(GMSPolyline *))completionHandler
{

    NSString *destLati= [NSString stringWithFormat:@"%f", destination.coordinate.latitude];
    NSString *destLongi= [NSString stringWithFormat:@"%f", destination.coordinate.longitude];


    NSString *originString = [NSString stringWithFormat:@"%f,%f", origin.coordinate.latitude, origin.coordinate.longitude];
    NSString *destinationString = [NSString stringWithFormat:@"%f,%f", destination.coordinate.latitude, destination.coordinate.longitude];
    NSString *directionsAPI = @"https://maps.googleapis.com/maps/api/directions/json?";
    NSString *directionsUrlString = [NSString stringWithFormat:@"%@&origin=%@&destination=%@&mode=driving", directionsAPI, originString, destinationString];
    NSURL *directionsUrl = [NSURL URLWithString:directionsUrlString];


    NSURLSessionDataTask *fetchDirectionsTask = [[NSURLSession sharedSession] dataTaskWithURL:directionsUrl completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {

        NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
        if(error)
        {
            if(completionHandler)
                completionHandler(nil);
            return;
        }

        NSArray *routesArray = [json objectForKey:@"routes"];

        __block  GMSPolyline *polyline = nil;

        if ([routesArray count] > 0)
        {
            NSDictionary *routeDict = [routesArray objectAtIndex:0];
            NSDictionary *routeOverviewPolyline = [routeDict objectForKey:@"overview_polyline"];
            NSString *points = [routeOverviewPolyline objectForKey:@"points"];

            dispatch_async(dispatch_get_main_queue(), ^{
                GMSPath *path = [GMSPath pathFromEncodedPath:points];
                polyline = [GMSPolyline polylineWithPath:path];
                polyline.strokeColor = [UIColor redColor];//[UIColor colorWithRed:156/255.0f green:52/255.0f blue:104/255.0f alpha:1.0];
                polyline.strokeWidth = 3.1f;
                polyline.map = mapViewGMS ;


                // add marker on source location
                CLLocationCoordinate2D source = CLLocationCoordinate2DMake(origin.coordinate.latitude,origin.coordinate.longitude );
                GMSMarker *markerSource = [GMSMarker markerWithPosition:source];
                // markerSource.title =  [NSString stringWithFormat:@"Estimated Start Trip at %@",globalTripStartTime];
                markerSource.icon=[UIImage imageNamed:@"markerGreenCircle"];
                markerSource.appearAnimation=0.2f;
                markerSource.map = mapViewGMS;

                // add marker on destination location
                CLLocationCoordinate2D destiCordin = CLLocationCoordinate2DMake([destLati floatValue],[destLongi floatValue] );
                GMSMarker *markerDestination = [GMSMarker markerWithPosition:destiCordin];
                //markerDestination.title = [NSString stringWithFormat:@"Estimated End Trip at %@",globalTripEndTime];
                markerDestination.icon=[UIImage imageNamed:@"markerRedCircle"];
                markerDestination.appearAnimation=0.2f;

                markerDestination.map = mapViewGMS;

                // Focus map on pick up location, first find center b/w 2 locations

                CLLocationCoordinate2D midpointBetweenCoordinate= [self midpointBetweenCoordinate:origin andCoordinate:destination];

                GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:midpointBetweenCoordinate.latitude
                                                                        longitude:midpointBetweenCoordinate.longitude
                                                                             zoom:10.5];

                mapViewGMS.camera=camera;
            });
        }

        if(completionHandler)
            completionHandler(polyline);
    }];

    [fetchDirectionsTask resume];
}