Question

我的应用需要跟踪用户当前位置。我正在使用LocationServices FusedLocationApi这样做。问题是当用户安装我的应用并启动应用时，我的应用无法跟踪用户位置。这个问题只是第一次出现。然后，每当我的应用程序打开该活动，我没有遇到任何问题。我的应用程序能够跟踪用户位置。

@Override
    public void onConnected(Bundle bundle) {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
                Log.d(APP_TAG,"A");

            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)) {
                // Display UI and wait for user interaction
            } else {
                // Check Permissions Now
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                        REQUEST_LOCATION);
            }

            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            //return;
        }
        //DevicePreferences.getGoogleApiClient().connect();

        //LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);

        LocationServices.FusedLocationApi.getLocationAvailability(mGoogleApiClient);

             /*mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                    mGoogleApiClient);*/



            mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                    mGoogleApiClient);




        Log.d(APP_TAG,""+mLastLocation);












        /*while (mLastLocation == null){

            mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                    mGoogleApiClient);
        }*/


        if (mLastLocation != null) {
            changeMap(mLastLocation);
            Log.d(APP_TAG, "ON connected");

        } else
           try {
                Log.d(APP_TAG, "B");

               LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);

                /*LocationServices.FusedLocationApi.removeLocationUpdates(
                        mGoogleApiClient, this);*/

           } catch (Exception e) {
             e.printStackTrace();
            }
        try {
            LocationRequest mLocationRequest = new LocationRequest();
            mLocationRequest.setInterval(10000); //10000
            mLocationRequest.setFastestInterval(1000); //5000

           // mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
            LocationServices.FusedLocationApi.requestLocationUpdates(
                    mGoogleApiClient, mLocationRequest, this);
            Log.d(APP_TAG,"4");
            mGoogleApiClient.connect();

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

Answer 1

初始化您的 mGoogleApiClient ，如果您还没有，请执行以下操作：

mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API).build();

如果，还有其他任何问题，请详细描述，使用更多代码

当用户第一次使用lauch app时，LocationServices.FusedLocationApi.getLastLocation（mGoogleApiClient）返回null

1 个答案: