如何使用 Android LocationManager 和 Listener

How to use Android LocationManager and Listener(如何使用 Android LocationManager 和 Listener)

问题描述

我没有任何运气使用下面的代码从 GPS 接收任何数据，我不确定我做错了什么，我的代码似乎与我在网上看到的所有内容相匹配.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已打开并且速度大于某个定义的量，但此时我不能甚至可以显示任何数据.我对 android 比较陌生，但我不知道我做错了什么?

I'm not having any luck receiving any data from the GPS using the code below, and i'm not sure what I'm doing wrong, it seems like my code matches everything i see online. i'd like to eventually add this to a background service to log gps coordinates even when the activity isn't visible or if other apps are open and if the speed is greater than a certain defined amount, but at this point I can't even get any of the data to show up. i'm relatively new to android but i can't figure out what am i doing wrong?

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()+"
"+"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) {}
}
}

推荐答案

试试下面的代码 -

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 -

Now put these line into your activity -

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();
}

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