如何使用Android LocationManager和Listener

Question

我没有运气从使用下面的代码接收GPS的任何数据，我不知道我做错了什么，似乎我的代码匹配我在网上看到的一切。 我想最终将此添加到后台服务以记录gps坐标，即使活动不可见或其他应用程序打开且速度大于某个定义的数量，但此时我不能甚至可以显示任何数据。 我对android比较新，但我无法弄清楚我做错了什么？

public class MainActivity extends Activity {
TextView textView;
MyLocationListener myLocationListener;
LocationManager lm;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    this.textView = (TextView)findViewById(R.id.message);
    addLocationListener();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

private void addLocationListener()
{
    lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

    Criteria c = new Criteria();
    c.setAccuracy(Criteria.ACCURACY_FINE);

    final String PROVIDER = lm.getBestProvider(c, true);

    this.myLocationListener = new MyLocationListener();
    this.lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0L, 0.0F, this.myLocationListener);
    //lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0L, 0.0F, myLocationListener);
    Log.d("LOC_SERVICE", "Service RUNNING!");
}

public void updateLocation(Location location)
{
    double latitude, longitude;

    latitude = location.getLatitude();
    longitude = location.getLongitude();
    int mph = convertSpeed(location.getSpeed());
    Log.d("LOC_SERVICE", "mph: "+mph);
    this.textView.setText(this.textView.getText()+"\n"+"lat: "+latitude+" lng: "+longitude+" mph: "+mph);
}


private int convertSpeed(float speed) {
    int mph =(int)(2.236936D * speed);
    return mph;
}


class MyLocationListener implements LocationListener {
    @Override
    public void onLocationChanged(Location location) {
        Log.d("LOC_SERVICE", "Listener RUNNING!");
        updateLocation(location);
    }
    @Override
    public void onProviderDisabled(String provider) {}
    @Override
    public void onProviderEnabled(String provider) {}
    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {}
}
}

Answer 1

试试以下代码 -

package com.muslimcompanion.utills;

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;

public class GPSTracker extends Service implements LocationListener {

    private final Context mContext;

    // flag for GPS status
    boolean isGPSEnabled = false;

    // flag for network status
    boolean isNetworkEnabled = false;

    // flag for GPS status
    boolean canGetLocation = false;

    Location location; // location
    double latitude; // latitude
    double longitude; // longitude

    // The minimum distance to change Updates in meters
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;

    public GPSTracker(Context context) {
        this.mContext = context;
        getLocation();
    }

    public Location getLocation() {
        try {
            locationManager = (LocationManager) mContext
                    .getSystemService(LOCATION_SERVICE);

            // getting GPS status
            isGPSEnabled = locationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);

            // getting network status
            isNetworkEnabled = locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
                // no network provider is enabled
            } else {
                this.canGetLocation = true;
                // First get location from Network Provider
                if (isNetworkEnabled) {
                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("Network", "Network");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
                // if GPS Enabled get lat/long using GPS Services
                if (isGPSEnabled) {
                    if (location == null) {
                        locationManager.requestLocationUpdates(
                                LocationManager.GPS_PROVIDER,
                                MIN_TIME_BW_UPDATES,
                                MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                        Log.d("GPS Enabled", "GPS Enabled");
                        if (locationManager != null) {
                            location = locationManager
                                    .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            if (location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                }
            }

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

        return location;
    }


    public void stopUsingGPS(){
        if(locationManager != null){
            locationManager.removeUpdates(GPSTracker.this);
        }       
    }


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

        // return latitude
        return latitude;
    }


    public double getLongitude(){
        if(location != null){
            longitude = location.getLongitude();
        }

        // return longitude
        return longitude;
    }


    public boolean canGetLocation() {
        return this.canGetLocation;
    }


    public void showSettingsAlert(){
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
                dialog.cancel();
            }
        });


        alertDialog.setCancelable(false);
        alertDialog.show();
    }

    @Override
    public void onLocationChanged(Location location) {
    }

    @Override
    public void onProviderDisabled(String provider) {
    }

    @Override
    public void onProviderEnabled(String provider) {
    }

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

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

}

现在将这些行放入您的活动中 -

GPSTracker gps = new GPSTracker(this);
int status = 0;
if(gps.canGetLocation())

{
    status = GooglePlayServicesUtil
            .isGooglePlayServicesAvailable(getApplicationContext());

    if (status == ConnectionResult.SUCCESS) {
        current_lattitude = gps.getLatitude();
        current_longitude = gps.getLongitude();
        _appPrefs.saveSmsBody("" + current_lattitude);
        _appPrefs.saveSmsBody("" + current_longitude);
        Log.d("dashlatlongon", "" + current_lattitude + "-"
                + current_longitude);

        if (current_lattitude == 0.0 && current_longitude == 0.0) {
            current_lattitude = 22.22;
            current_longitude = 22.22;

        }

    } else {
        current_lattitude = 22.22;
        current_longitude = 22.22;
    }

}
else
{
    gps.showSettingsAlert();
}

Answer 2

您需要先使用权限：

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

接下来你在onCreate（）方法中使用下面的代码来访问GPS。

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

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

    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
            2000, 1, this);

}

现在如果没有启用GPS，那么您需要参考下面的代码。 有关详细说明，您可以参考如何获取[DEAD LINK] [android中的当前位置] 1教程。

Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
         startActivity(intent);

在这里，我们使用意图将用户重定向到位置设置页面，以便他可以在位置设置下启用GPS。

Answer 3

你可以轻松实现这一目标。 你必须在主要活动中编写代码。 和Main活动实现Locationlistner接口。 并超载其四种方法。 这里我在应用程序启动时在textview中检索我的经度和Latitide坐标。 并且您必须在清单文件中授予访问位置的权限。

在我的代码下。

package com.nisarg.gpsdemo;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements LocationListener {

    private LocationManager locationManager;
 private TextView textview;

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

        textview=(TextView)findViewById(R.id.textView);

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

        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;
        }
        Location location = locationManager.getLastKnownLocation(locationManager.NETWORK_PROVIDER);

        onLocationChanged(location);
    }

    @Override
    public void onLocationChanged(Location location) {
        double longitude=location.getLongitude();
        double latitude=location.getLatitude();
        textview.setText("Longitude:   "+longitude+"   Latitide:  "+latitude);

    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

    }

    @Override
    public void onProviderEnabled(String s) {

    }

    @Override
    public void onProviderDisabled(String s) {

    }
}

你必须在清单文件中给出这样的许可。

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

最后警告。 在打开应用程序之前，您必须授予您的应用程序许可并启动移动数据和GPS。 要么它会崩溃。

而已。 希望它会对你有所帮助。 :)