无法从 gps 获取位置

Posted 2023-04-14

【中文标题】无法从 gps 获取位置

【英文标题】：Unable to get location from gps

【发布时间】：2017-09-19 17:41:39

【问题描述】：

我正在尝试创建一个从用户的 gps 获取纬度和经度的应用程序，这是我正在使用的类：-

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) 
                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 TODO;
                    Toast.makeText(this,"It's very important that you agree to gps permission, kindly restart the app and accept",Toast.LENGTH_LONG).show();

                
                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;

当我在 MainActivity 中调用此函数时，它从不要求任何权限，也不会显示任何错误，这是我正在使用的函数：-

String getlocurl()
    GPSTracker gps;
    gps = new GPSTracker(MainActivity.this);
    double latitude = 0;
    double longitude = 0;
    if(gps.canGetLocation())
        latitude = gps.getLatitude();
        longitude = gps.getLongitude();
        String lat = String.valueOf(latitude);
        String lng = String.valueOf(longitude);
        String mapurl = "https://www.google.com/maps/preview/@"+lat+","+lng+","+"8z";
        return mapurl;
    
    else
        // can't get location
        // GPS or Network is not enabled
        // Ask user to enable GPS/network in settings
        gps.showSettingsAlert();
        return "error";
    

这是我得到的结果：“https://www.google.com/maps/preview/@0.0,0.0,8z” 它返回 0.0,0.0 作为纬度和经度，我该如何解决？

【问题讨论】：

***.com/questions/43082062/…

【参考方案1】：

将此放在您的清单文件中 application 标签之前：

<uses-permission android:name="android.permission.INTERNET" />                  <!-- verify if connected to the internet -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />      <!-- verify if connected to any network -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />      <!-- verify location using GPS, give precise location -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />    <!-- verify location using WiFi and mobile, gives approximate location -->