Remove marker in google_maps_flutter

user_10253232 0
Viewed 10852

I have added Google Maps for Flutter i know how to add a marker as it is given clearly in there examples

MarkerOptions _options = new MarkerOptions(
          position: LatLng(
            driver_lat,
            driver_lng,
          ),
          infoWindowText:
              const InfoWindowText('An interesting location', '*'));

      Marker marker = new Marker('1', _options);

      //Adding Marker
      googleMapController.addMarker(_options);

And i am removing the marker like below

googleMapController.removeMarker(marker);

for adding the marker it is taking MarkerOptions object as a parameter but for removing the marker it is asking for Marker object as parameter and my removing marker code is not working. i am getting the below error

Failed assertion: line 201 pos 12: '_markers[marker._id] == marker': is not true.
flutter google-maps-markers google-maps
5 Answers

There are two ways to do this, one is via clearMarkers() Method

mapController.clearMarkers();

Another one is via targeting each marker returned by mapController.markers

mapController.markers.forEach((marker){
      mapController.removeMarker(marker);
});
user_22027570

2020 answer:

.clearMarkers() has been deprecated as now each Marker is a Widget stored in a map. The correct way to clear all of the markers now on your Google Map is to set the state of of your marker Map to an empty map.

e.g.

                ...
                  onPressed: () {
                    setState(() {
                      gMapMarkers = {};
                    });
                  }
                ....
user_64483120

Use clearMarkers(). It will clear all markers in your map. So try googleMapController.clearMarkers();

user_106985590

I've came across this issue myself with the google_maps_library and the main cause of this issue '_markers[marker._id] == marker': is not true. is the fact that all GoogleMapsController methods return a Future, so this error is, let's say a concurrency issue since the method cals are async.

The correct way to add/remove a marker would be:

_testRemoveMarker() async {
    Marker marker = await _mapController.addMarker(...markerOption..);
    _mapController.removeMarker(marker);
} 

_clearMarkersAndRead() async {
   _mapController.clearMarkers().then((_) {
       //TODO: add makrers as you whish;
   });
}

So, if you do any operations with the markers add/remove/update, you should be sure that the previous operation that involved markers is completed.

user_23159740

If anyone still struggling with removing a specific marker try this method;

      MarkerId id = MarkerId("Pickup");
      //markers[id] = {} as Marker; clear all markers
      markers.removeWhere((key, value) => key == id); //clear a specific marker
user_89363890
Related