如何单击地图上多个标记中的一个标记，然后转到包含标记信息的活动

Question

I want to create multiple markers on a map, each marker will have information, such as location, address..., and when I click the marker, another activity will show up and show the info of the marker I clicked, and I wrote some codes, the result turns out to be that, for different markers, the info transferred from the markers to the activity is the same, the code is like following:

for (final MyMarkerData object: aaa) {
        m = googleMap.addMarker(new MarkerOptions()
                .position(object.getLatLng())
                .title(object.getTitle())
                .snippet(object.getSnippet()));
        googleMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
            @Override
            public boolean onMarkerClick(Marker m) {
                Intent intent = new Intent(getActivity(), EventInfo.class);
                intent.putExtra("title", object.getTitle());
                startActivity(intent);
                return false;
            }
        });
      }

the code in the activity is like:

Intent intent = getIntent();
    String a = intent.getStringExtra("title");
    TextView textview  =  findViewById(R.id.eventInfo);
    textview.setText(a);

when I click three different markers, the TextView showed the same info(actually is different), which is the last info in ArrayList aaa, so what's wrong with this?

Answer 1

googleMap use only 1 OnMarkerClickListener for every Marker clicked event so you set it multiple times in a for loop is useless, the last one will override the previous listener. That's why only the last listener is registered.

Two things to refactor here: - Call setOnMarkerClickListener only 1 time is enough - Define a HashMap<Marker, object> to get the right object from the clicked marker

HashMap<Object, Marker> markerMap = new HashMap<Object, Marker>();

googleMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
    @Override
    public boolean onMarkerClick(Marker m) {
        Object obj = markerMap.get(m);

        // Use obj for correct data object
    }
});

for (final MyMarkerData object: aaa) {
    marker = googleMap.addMarker(new MarkerOptions()
            .position(object.getLatLng())
            .title(object.getTitle())
            .snippet(object.getSnippet()));

    markerMap.put(aaa, marker)
}