Question

我正在构建一个使用带有位置监听器的Google地图的Android应用程序。当地图第一次出现时，我在位置监听器中将缩放设置为12，我在谷歌地图开发方面相当新，所以我想知道如何在用户捏住更改缩放后如何更新位置而不影响缩放？下面是我的位置听众。

/**
 *Mylocationlistener class will give the current GPS location 
 *with the help of Location Listener interface 
 */
private class Mylocationlistener implements LocationListener {

    @Override
    public void onLocationChanged(Location location) {

        if (location != null) {
            // ---Get current location latitude, longitude---

            Log.d("LOCATION CHANGED", location.getLatitude() + "");
            Log.d("LOCATION CHANGED", location.getLongitude() + "");
            currentLocation = new LatLng(location.getLatitude(), location.getLongitude());
            currentLatLng = new LatLng(location.getLatitude(), location.getLongitude());
            Marker currentLocationMarker = map.addMarker(new MarkerOptions().position(currentLocation).title("Current Location"));
            // Move the camera instantly to hamburg with a zoom of 15.
            map.moveCamera(CameraUpdateFactory.newLatLngZoom(currentLatLng, 15));
            // Zoom in, animating the camera.
            map.animateCamera(CameraUpdateFactory.zoomTo(12), 2000, null);
            if (!firstPass){
                currentLocationMarker.remove();
            }
            firstPass = false;
            Toast.makeText(MapViewActivity.this,"Latitude = "+
                    location.getLatitude() + "" +"Longitude = "+ location.getLongitude(),
                    Toast.LENGTH_LONG).show();

        }
    }

Answer 1

您可以在侦听器中添加局部变量，并使用它仅缩放第一个位置。代码看起来像：

private class Mylocationlistener implements LocationListener {

   private boolean zoomed = false;

   @Override
   public void onLocationChanged(Location location) {

    if (location != null) {
        // ---Get current location latitude, longitude---

        Log.d("LOCATION CHANGED", location.getLatitude() + "");
        Log.d("LOCATION CHANGED", location.getLongitude() + "");
        currentLocation = new LatLng(location.getLatitude(), location.getLongitude());
        currentLatLng = new LatLng(location.getLatitude(), location.getLongitude());
        Marker currentLocationMarker = map.addMarker(new MarkerOptions().position(currentLocation).title("Current Location"));
        // Move the camera instantly to hamburg with a zoom of 15.
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(currentLatLng, 15));
        // Zoom in, animating the camera.
        if (!zoomed) {
            map.animateCamera(CameraUpdateFactory.zoomTo(12), 2000, null);
            zoomed = true;
        }                                       
        if (!firstPass){
            currentLocationMarker.remove();
        }
        firstPass = false;
        Toast.makeText(MapViewActivity.this,"Latitude = "+
                location.getLatitude() + "" +"Longitude = "+ location.getLongitude(),
                Toast.LENGTH_LONG).show();

    }
}

Answer 2

尝试使用此功能：

map.animateCamera(CameraUpdateFactory.newLatLngZoom(currentLocationMarker.getPosition(), map.getCameraPosition().zoom));

如何在不更改用户设置的缩放的情况下更新地图标记？

2 个答案: