显示位置并将相机置于其中心的问题

Question

由于奇怪的原因，我刚刚遇到了 CameraUpdateFactory 的一些问题。

所以我将这段代码合并到导航片段上 GpsButton 的 onclickListener 中：

 if (ContextCompat.checkSelfPermission(mapFragment.getActivity(), android.Manifest.permission.ACCESS_FINE_LOCATION) ==
                    PackageManager.PERMISSION_GRANTED) {
                Log.d("Permission checked", "checkSelfPermission passed with no errors");
                map.setMyLocationEnabled(true);
                Log.d("Permission checked", "Location Layer implementation successful");
            } else {
                //Request the Permission
                ActivityCompat.requestPermissions(mapFragment.getActivity(), new String[]{
                        Manifest.permission.ACCESS_FINE_LOCATION}, 1);
            }

这基本上可以使位置仅在按下 GPS 按钮时在地图上显示为蓝点。到目前为止，这是完美的功能。

我还采用了一种将相机移动到我当前位置的方法：

 public void locateMe() {

    LocationManager locationManager = (LocationManager) getActivity().getSystemService(LOCATION_SERVICE); // Getting LocationManager object from System Service LOCATION_SERVICE
    Criteria criteria = new Criteria();// Creating a criteria object to retrieve provider
    String provider = locationManager.getBestProvider(criteria, true);// Getting the name of the best provider
    if (ContextCompat.checkSelfPermission(mapFragment.getActivity(), android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(mapFragment.getActivity(), new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 2);
    }
    Location location = locationManager.getLastKnownLocation(provider);

    if (location != null) {

        double latitude = location.getLatitude(); //Getting latitude of the current location
        double longitude = location.getLongitude(); // Getting longitude of the current location
        myPosition = new LatLng(latitude, longitude); // Creating a LatLng object for the current location
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(myPosition, CAMPUS_DEFAULT_ZOOM_LEVEL));//Camera Update method
    }
}

出于某种原因，这是成功或失败的。 3 天前，它锁定的位置不是我当前所在的位置，而过去 2 天它运行良好。没有任何代码被更改。有人可以解释一下发生了什么吗？任何修复或建议将不胜感激。

Answer 1

出现这种情况是因为您正在使用 getLastKnownLocation。

This can be done without starting the provider. Note that this location could be out-of-date, for example if the device was turned off and moved to another location. If the provider is currently disabled, null is returned.

documentation

如果您想检索用户的当前文档，则必须使用 requestLocation 更新。 requestLocationUpdates documentation

显示位置并将相机置于其中心的问题

Problems displaying a location and centering the camera on it

java

android

google-maps

geolocation

locationmanager