随着用户移动，定期将地图上的所有标记移动到其更新/新的当前位置 [英] Move all the markers on the map to their updated/new current location periodically as users moves

问题描述

我正在开发一个 android 应用程序，其中一些用户从他们的设备打开相同的活动.此 Activity 中有一张地图，当用户从其设备打开此 Activity 时，会从 Firebase 获取他们的位置坐标，并在地图上显示基于这些坐标的标记.

I'm developing an android app where some users opens the same activity from their devices. There is a map in this activity and as users opens this activity from their devices, their location coordinates is fetched from Firebase and a marker based on these coordinates is shown on the map.

这是我的代码:

acceptingUserReference.child(requestID).child(key).addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {

        if (dataSnapshot.getValue() != null) {
            final Map<String, String> newAcceptedUser = (Map<String, String>) dataSnapshot.getValue();
            
            nameOfP.add(newAcceptedUser.get("pName"));                      
            cLatP.add(newAcceptedUser.get("currentLat").trim());
            cLngP.add(newAcceptedUser.get("currentLng").trim());

            addMarkers();

            //Check map is loaded
            mMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
                @Override
                public void onMapLoaded() {
                    mMap.getUiSettings().setZoomControlsEnabled(true);
                    mMap.getUiSettings().setMapToolbarEnabled(true);
                    mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
                    mMap.setMaxZoomPreference(19.0f);  mMap.setMyLocationEnabled(true);

                }
            });
            
            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }
}   
    

这里是 addMarkers() 方法:

public void addMarkers() {
    mMap.clear();
    venueMarker = mMap.addMarker(new MarkerOptions().position(new LatLng(Double.parseDouble(venueLat), Double.parseDouble(venueLng)));
    markersList.add(venueMarker);
    for (int i = 0; i < nameOfP.size(); i++) {
        p = mMap.addMarker(new MarkerOptions().position(new LatLng(Double.valueOf(cLatP.get(i)), Double.valueOf(cLngP.get(i)))).title(nameOfP.get(i).trim()).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED)));
        markersList.add(pMarker);
    }
}

这是onLocationChanged():

@Override
public void onLocationChanged(Location location) {
    mCurrentLocation = location;
    currentLtAU = mCurrentLocation.getLatitude();
    currentLnAU = mCurrentLocation.getLongitude();
}

用户不断向特定位置移动.

我想要的是在用户移动时将相应的标记移动到新位置，这样每个人都可以看到每个人当前所在的位置.请帮我弄清楚.

What I want is to move the respective markers to the new location as the users moves so that everybody can see where each and everyone currently is. Please help me figure it out.

推荐答案

1. 每当 onLocationChanged 调用意味着用户移动了一段距离.

1. Whenever onLocationChanged called means user moved to some distance.

在 onLocationChanged 中更新用户在 Firebase 上的更新位置，以便其他用户可以找到您更新的位置.

Update user's updated location on Firebase in onLocationChanged so, other user can find your updated location.

注意:使用 geofire 更新用户位置并查看这个答案.

Note: use geofire to update user location and see this answer.

@Override
public void onLocationChanged(Location location) {
mCurrentLocation = location;
currentLtAU = mCurrentLocation.getLatitude();
currentLnAU = mCurrentLocation.getLongitude();
}

2. 在您成功将用户位置更新到 Firebase

2. call acceptingUserReference.child(requestID) code when you successfully update user location to Firebase

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