android - 即使使用融合位置 API 关闭 gps，如何获取位置更新？

Question

这个问题可能会被问很多次，但我找不到任何解决方案。我需要在后台获取用户的位置 15 分钟。

当 GPS 打开时，它工作正常，但当 GPS 关闭时，应用程序无法获取位置更新。我需要它至少获取网络位置或 wifi 位置。

如何使用融合位置 API 实现此目的？

位置管理器具有此功能，但处于融合位置。因为 Google 建议开发人员使用播放服务 API 中的位置，所以我不想使用位置管理器。我怎样才能做到这一点，所以让我发布到目前为止我尝试过的内容:

import android.content.Context;
import android.location.Location;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.util.Log;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.FusedLocationProviderApi;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

/**
 * Created by 4264 on 14-10-2016.
 */

public class Locationlistener implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener,LocationListener  {


    private Location mlocation; // location
    private double latitude; // latitude
    private double longitude; // longitude
    private GoogleApiClient mGAC;
    private Context mContext;
    public static final String TAG = "GPSresource";
    private FusedLocationProviderApi fusedLocationProviderApi;
    private LocationRequest locationRequest;

    public Locationlistener(Context c)
    {
        mContext = c;
        try {
            buildGoogleApiClient();
            mGAC.connect();
        }
        catch(Exception e)
        {
            Log.d(TAG,e.toString());
        }
    }

    protected synchronized void buildGoogleApiClient() {
        locationRequest = LocationRequest.create();
        locationRequest.setPriority(LocationRequest.PRIORITY_LOW_POWER);
        locationRequest.setInterval(1);
        locationRequest.setFastestInterval(1);
        mGAC = new GoogleApiClient.Builder(mContext)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
       }


    public double getLatitude(){
        if(mlocation != null){
            latitude = mlocation.getLatitude();
        }

        // return latitude
        return latitude;
    }

    /**
     * Function to get longitude
     * */
    public double getLongitude() {
        if (mlocation != null) {
            longitude = mlocation.getLongitude();
        }

        // return longitude
        return longitude;
    }

    public Location GetLocationBlocking() throws InterruptedException {



        //      String lat=String.valueOf(moCurrentLocation.getLatitude());
        //    String longt=String.valueOf(moCurrentLocation.getLongitude());
//        Toast.makeText(oContext,"Lat"+lat+"long"+longt,Toast.LENGTH_SHORT).show();
        return mlocation;

    }


    @Override
    public void onConnected(Bundle bundle) {
            Location oLocation = LocationServices.FusedLocationApi.getLastLocation(mGAC);
            if (mGAC != null) {

                mlocation = oLocation;
            getLatitude();
            getLongitude();
            if (oLocation != null){
              Log.d("lat",String.valueOf(mlocation.getLatitude()));
            Log.d("long",String.valueOf(mlocation.getLongitude()));
            }
            else{
                LocationServices.FusedLocationApi.requestLocationUpdates(mGAC, locationRequest, this);
        }   }}


    @Override
    public void onConnectionSuspended(int i) {

    }




    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }

    @Override
    public void onLocationChanged(Location location) {
        mlocation=location;
    }
}

Answer 1

我不明白你说你不想使用位置管理器和 GPS...看看这个 Location Strategies ...基于此文档，我们有 3 种访问位置的策略:

1. 全局定位系统
2. 网络位置提供商
3. 或同时使用

但是对于您的位置问题，这是我的提议:在 Activity 中，放置以下内容以连接并开始接收位置更新:

private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;

private long UPDATE_INTERVAL = 10 * 1000;  /* 10 secs */
private long FASTEST_INTERVAL = 2000; /* 2 sec */

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    // Create the location client to start receiving updates
    mGoogleApiClient = new GoogleApiClient.Builder(this)
                          .addApi(LocationServices.API)
                          .addConnectionCallbacks(this)
                          .addOnConnectionFailedListener(this).build();
}

protected void onStart() {
    super.onStart();
    // Connect the client.
    mGoogleApiClient.connect();
}

protected void onStop() {
    // Disconnecting the client invalidates it.
    LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);

    // only stop if it's connected, otherwise we crash
    if (mGoogleApiClient != null) {
        mGoogleApiClient.disconnect();
    }
    super.onStop();
}

public void onConnected(Bundle dataBundle) {
    // Get last known recent location. 
    Location mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    // Note that this can be NULL if last location isn't already known.
    if (mCurrentLocation != null) {
      // Print current location if not null
      Log.d("DEBUG", "current location: " + mCurrentLocation.toString());
      LatLng latLng = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
    }
    // Begin polling for new location updates.
    startLocationUpdates();
}

@Override
public void onConnectionSuspended(int i) {
    if (i == CAUSE_SERVICE_DISCONNECTED) {
      Toast.makeText(this, "Disconnected. Please re-connect.", Toast.LENGTH_SHORT).show();
    } else if (i == CAUSE_NETWORK_LOST) {
      Toast.makeText(this, "Network lost. Please re-connect.", Toast.LENGTH_SHORT).show();
    }
}

// Trigger new location updates at interval
protected void startLocationUpdates() {
    // Create the location request
    mLocationRequest = LocationRequest.create()
        .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
        .setInterval(UPDATE_INTERVAL)
        .setFastestInterval(FASTEST_INTERVAL);
    // Request location updates
    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
        mLocationRequest, this);
}

然后使用 onLocationChanged 注册位置更新:

public void onLocationChanged(Location location) {
    // New location has now been determined
    String msg = "Updated Location: " +
        Double.toString(location.getLatitude()) + "," +
        Double.toString(location.getLongitude());
    Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
    // You can now create a LatLng Object for use with maps
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
}

有关 Fused Location API 的更多信息，请参阅 Make ypur app Location Aware位置更新疑难解答

位置更新应始终使用 GoogleApiClient 利用 LocationServices.API 完成，如上所示。不要使用不太可靠的旧位置 API。即使使用正确的 FusedLocationApi，也有很多地方可能出错。考虑以下潜在问题:

• 您是否添加了必要的权限？确保您的应用具有INTERNET 和 ACCESS_COARSE_LOCATION 权限以确保可以按照上面的指南中的说明访问位置。
• 调用时你得到的是空值吗LocationServices.FusedLocationApi.getLastLocation? 这是正常的因为此方法仅在已有位置时返回最近被另一个应用程序检索。如果这返回 null，这意味着您需要开始接收位置更新LocationServices.FusedLocationApi.requestLocationUpdates 之前接收如上所示的位置。
• 您是否尝试在 genymotion 模拟器上获取位置？确保您已启用 GPS 并正确配置了纬度/经度。尝试重新启动如果需要模拟器并重新启用 GPS 或尝试设备(或官方模拟器)而不是排除 genymotion 特定问题。