在Android中查找用户的当前位置

Question

我是 Android 新手，我正在尝试开发一个显示用户当前位置的 Android 应用程序。我正在使用 Genymotion。现在我正在使用

mLocation=LocationServices.FusedLocationApi.getLastLocation(mGoogleClient); 

获取设备的最后位置。问题是我想获得当前位置，但有了这个我得到mlocation 不为空，这很好。但在地图中，它始终显示设备的最后位置，而不是当前位置。

代码 sn-p

@Override
public void onConnected(Bundle bundle) {
    Log.i(TAG, "inside onconnected Location services connected");
    Location mLocation=null;
    mLocationRequest= new LocationRequest();
    mLocationRequest.setInterval(10 * 1000)    ;   
    mLocationRequest.setFastestInterval(1 * 1000);mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) !=
        PackageManager.PERMISSION_GRANTED &&
        ActivityCompat.checkSelfPermission(this,
        Manifest.permission.ACCESS_COARSE_LOCATION) !=
        PackageManager.PERMISSION_GRANTED) {

    }
               mLocation=LocationServices.FusedLocationApi.getLastLocation(mGoogleClient);
    if(mLocation==null)
    {
        Log.d("***Inside mlocation***", "***mlocation is null here");
    }

    if (mLocation != null) {
        onLocationChanged(mLocation);
    }
    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleClient, mLocationRequest, this);
}

@Override
public void onLocationChanged(Location location) {
    double currentLatitude = location.getLatitude();
    double currentLongitude = location.getLongitude();
    LatLng latLng = new LatLng(currentLatitude,currentLongitude);
    MarkerOptions options = new MarkerOptions()
            .position(latLng)
            .title("Im here!");

    mMap.addMarker(options);
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
}

在onstart() 中，我调用了googleapi.connect()，并适当地使用了setUpMapIfNeeded()。

请告诉我这段代码有什么问题。我正在尝试这个 3 天。

Answer 1

用代码发布简单的解决方案。

在 AndroidManifest.xml 文件中添加权限

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

如果您的应用与棉花糖兼容，请检查运行时权限。

在 gradle 文件中添加依赖：

compile 'com.google.android.gms:play-services:9.2.0'

在你的活动中实现这两个接口

GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener

和

在 oncreate 中像这样创建 googleapiclient 对象：

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

并在开始活动时进行此操作

mGoogleApiClient.connect();

我们在此覆盖方法上继续位置的结果回调。

public void onConnected(@Nullable Bundle bundle) {
    Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLastLocation != null) {
        Log.e(TAG, "onConnected: " + String.valueOf(mLastLocation.getLatitude()) + ":" + String.valueOf(mLastLocation.getLongitude()));
    } else {
        Toast.makeText(getApplicationContext(), "Your Location Not Found", Toast.LENGTH_LONG).show();
    }
}

完整的活动代码是这样的：

public class LocationActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {

private static final String TAG = LocationActivity.class.getSimpleName();

private GoogleApiClient mGoogleApiClient;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_location);


    // Create an instance of GoogleAPIClient.
    if (mGoogleApiClient == null) {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }
}

@Override
protected void onStart() {
// connect googleapiclient
    mGoogleApiClient.connect();
    super.onStart();
}

@Override
protected void onStop() {
// disconnect googleapiclient
    mGoogleApiClient.disconnect();
    super.onStop();
}

@Override
public void onConnected(@Nullable Bundle bundle) {
    Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLastLocation != null) {
    // here we go you can see current lat long.
        Log.e(TAG, "onConnected: " + String.valueOf(mLastLocation.getLatitude()) + ":" + String.valueOf(mLastLocation.getLongitude()));
    }
}

@Override
public void onConnectionSuspended(int i) {

}

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

}}

p.s. googleapiclient 无法在没有播放服务的模拟器中运行，因此您必须在真实设备上进行测试。 请确保在该设备上启用了 gps。

如果您想使用传统方法获取位置，请尝试本教程。 http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/

------更新 6 月 15 日---------

最新的api 检查安卓谷歌帖子： https://android-developers.googleblog.com/2017/06/reduce-friction-with-new-location-apis.html

Answer 2

对于地图服务，它需要 Google Play 服务。如果没有，请确保您的 Genymotion 已安装 PlayService 从Here 获得帮助以在 Genymotion 中安装 Google Play 服务。 快乐编码..!!!

Answer 3

     LocationListener locationListener;
        LocationManager locationManager;
        double latitude;
        double longitude;  


       locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);


        locationListener = new LocationListener()
        {
            @Override


            public void onLocationChanged(Location location) {

    longitude = location.getLongitude();
    latitude = location.getLatitude();
  }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {
            }

            @Override
            public void onProviderEnabled(String provider) {
            }

            @Override
            public void onProviderDisabled(String provider) {
            }
        };
        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)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.

            ;
        }
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000, 0, locationListener);



        Log.e("location", longitude + " " + latitude);