Java 在 Android Studio 应用中获取当前位置

Getting current location in Android Studio app

提问by RayzaN

I am developing my first Android app which should get the latitudeand longitudeof an android device and send it via a web service to a template document.

我正在开发我的第一个 Android 应用程序，它应该获取Android 设备的纬度和经度，并通过 Web 服务将其发送到模板文档。

I followed the guide of getting the location from http://developer.android.com/training/location/retrieve-current.html.

我按照从http://developer.android.com/training/location/retrieve-current.html获取位置的指南进行操作。

This is the code from my .java class:

这是我的 .java 类中的代码：

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;

public class GetLocation extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
    private GoogleApiClient mGoogleApiClient;
    EditText textLat;
    EditText textLong;
    EditText lat;
    EditText lon;

    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.get_location);

        textLat = (EditText) findViewById(R.id.latitude);
        textLong = (EditText) findViewById(R.id.longitude);

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

    private boolean isGPSEnabled() {
        LocationManager cm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        return cm.isProviderEnabled(LocationManager.GPS_PROVIDER);
    }

    @Override
    public void onConnected(Bundle bundle) {
        Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if (mLastLocation != null) {
            lat.setText(String.valueOf(mLastLocation.getLatitude()));
            lon.setText(String.valueOf(mLastLocation.getLongitude()));
        }
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

    }

    public void onButtonClick(View v){
        if(v.getId() == R.id.getGpsLocation){
            if(!isGPSEnabled()){
                new AlertDialog.Builder(this)
                        .setMessage("Please activate your GPS Location!")
                        .setCancelable(false)
                        .setPositiveButton("Settings", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                                startActivity(i);
                            }
                        })
                        .setNegativeButton("Cancel", null)
                        .show();
            } else {
                textLat.setText(String.valueOf(lat));
                textLong.setText(String.valueOf(lon));
            }

        }
    }


}

I don't get any errors but when I am tapping the button which should get the coordinates, I get 'null' text in both views.

我没有收到任何错误，但是当我点击应该获取坐标的按钮时，我在两个视图中都得到了“空”文本。

I also have included permissions for internet, access fine and coarse location.

我还包括了互联网的权限，访问精细和粗略的位置。

Thanks in advance!

提前致谢！

回答by KishuDroid

You need to define LocationListener .

您需要定义 LocationListener 。

public class MainActivity extends Activity implements LocationListener{
    protected LocationManager locationManager;
    protected LocationListener locationListener;
    protected Context context;
    TextView txtLat;
    String lat;
    String provider;
    protected String latitude,longitude; 
    protected boolean gps_enabled,network_enabled;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        txtLat = (TextView) findViewById(R.id.textview1);

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
    }
    @Override
    public void onLocationChanged(Location location) {
        txtLat = (TextView) findViewById(R.id.textview1);
        txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
    }

    @Override
    public void onProviderDisabled(String provider) {
        Log.d("Latitude","disable");
    }

    @Override
    public void onProviderEnabled(String provider) {
        Log.d("Latitude","enable");
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        Log.d("Latitude","status");
    }
}

And need to give below permission :

并需要给予以下许可：

ACCESS_COARSE_LOCATION: It is used when we use network location provider for our Android app.

ACCESS_COARSE_LOCATION：当我们为我们的 Android 应用程序使用网络位置提供程序时使用它。

ACCESS_FINE_LOCATION: It is providing permission for both providers.

ACCESS_FINE_LOCATION：它为两个提供者提供许可。

INTERNET: permission is must for the use of network provider.

INTERNET: 使用网络提供商必须获得许可。

回答by Keith

Here is a working example of user location:

这是用户位置的工作示例：

https://github.com/keithweaver/Android-Samples/tree/master/Location

https://github.com/keithweaver/Android-Samples/tree/master/Location

回答by Parsania Hardik

I have written detailed tutorial covering this topic here on demonuts.com.You can find more description here and also you can download whole demo source code for better understanding.

我在deviluts.com上写了详细的教程，涵盖了这个主题。你可以在这里找到更多的描述，也可以下载整个演示源代码以更好地理解。

First of all, put this in gradle file

首先，把它放在gradle文件中

 compile 'com.google.android.gms:play-services:9.0.2'

then implement necessary interfaces

然后实现必要的接口

public class MainActivity  extends BaseActivitiy implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener

declare instances

声明实例

  private GoogleApiClient mGoogleApiClient;
  private Location mLocation;
  private LocationManager locationManager;
  private LocationRequest mLocationRequest;

put this in onCreate()

把这个放进去 onCreate()

 mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

At last, override necessary methods

最后，覆盖必要的方法

 @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)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        } startLocationUpdates();
        mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if(mLocation == null){
            startLocationUpdates();
        }
        if (mLocation != null) {
            double latitude = mLocation.getLatitude();
            double longitude = mLocation.getLongitude();
        } else {
            // Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show();
        }
    }

    protected void startLocationUpdates() {
        // Create the location request
        mLocationRequest = LocationRequest.create()
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setInterval(UPDATE_INTERVAL)
                .setFastestInterval(FASTEST_INTERVAL);
        // Request location updates
        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.
            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
                mLocationRequest, this);
        Log.d("reque", "--->>>>");
    }

    @Override
    public void onConnectionSuspended(int i) {
        Log.i(TAG, "Connection Suspended");
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode());
    }

    @Override
    public void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    @Override
    public void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }
    @Override
    public void onLocationChanged(Location location) {

    }

Don't forget to start GPS in your device before running app.

在运行应用程序之前，不要忘记在您的设备中启动 GPS。